Each slice of this easy egg breakfast casserole is thick, flavorful, and satisfying; plus, the recipe is an incredibly convenient breakfast choice since it’s make-ahead and infinitely adaptable. Like quiche and breakfast egg muffins, you can use your favorite seasonings and cheeses, vegetables like peppers and mushrooms, meats like sausage or bacon, or you can make it vegetarian. The best part is that you can assemble this dish ahead of time so breakfast is a breeze in the morning!
I originally published this recipe in 2015 and have since added new photos, a video tutorial, and more helpful success tips. I’ve also simplified the recipe instructions.
Breakfast casserole is an all-in-one hearty meal that can be made ahead of time, feeds a crowd, reheats well, and makes great leftovers. My family devours it. For all these reasons and more, I’ve made it nearly 100x (no exaggeration there) for breakfast, brunch, and, yes, dinner. It’s one of my favorite Easter brunch recipes to serve each year, too.
Let me show you how it comes together so you too can experience this crowd-pleasing superhero meal.
One reader, Mary, commented: “Love it! It is literally the perfect recipe. I’ve made it a few times now and everyone loves it, including my in-laws. We’ve made it for a crowd and also done it for the week as a meal prep for my husband and I. We love that it’s all in one (protein, veggies, carbs, etc.), easy to make, and can be made ahead. I cannot recommend this recipe enough! ★★★★★“
This Easy Breakfast Casserole Is:
- Adaptable to whatever vegetables, meats, cheeses, and herbs you have on hand.
- Easy to make ahead of time.
- Quick to throw together.
- Great as a quick weekday meal or a lavish weekend or holiday brunch.
- Excellent for entertaining a crowd.
- Made with some bread to soak up moisture, but potatoes work too!
- Ready for your favorite egg toppings like salsa, pico de gallo, green onion, cilantro, parsley, avocado, everything bagel seasoning, hot sauce, etc.
4 Main Components
When gathering ingredients for this recipe, I like to think of it as having 4 separate components. From there, you can have fun with variations.
- Vegetables
- Meat (or extra vegetables)
- Starch for soaking up moisture
- Egg, cheese, & milk mixture
Here Are the Endless Add-ins & Flavor Options
- Vegetables: Select which vegetables you’d like in the dish. Generally, the most popular with guests is bell peppers, spinach, and mushrooms. But I’ve also made this with broccoli/peppers, kale/mushrooms, and spinach/zucchini. Try to stick to 3–4 cups of vegetables total. Cook the vegetables down with some flavor-enhancing onion and garlic.
- Meat: Guests usually prefer meat in the casserole, so I add sausage. Or try using ground turkey, chopped bacon, ground beef, or ground chicken. I usually purchase uncooked sausage for this and brown it with some dried rosemary or Italian seasoning to give it a little extra flavor, but that is optional. If the meat you’re using is pre-cooked, such as chopped ham or shredded chicken, you can mix it with the cooked vegetable mixture before layering it into the dish.
- Starch: Like when making sausage & herb stuffing, breakfast strata, and French toast casserole, the bread should be slightly stale so it can soak up moisture. Crusty sourdough or homemade ciabatta bread are FANTASTIC here. You can also use homemade artisan bread, seeded oat bread, whole wheat bread, a loaf of French bread, crusty baguette, biscuits, bagels or homemade bagels, or even day-old croissants (have you tried homemade croissants?!). To make it gluten free, use gluten-free bread or potatoes.
- Eggs, milk, & cheese: Whisk a dozen eggs with a little half-and-half or milk and stir in some shredded cheese. Like the vegetables and meat, use whatever cheeses you like best, such as sharp cheddar, pepper jack, feta, and/or smoked gouda.
Variations: One of my favorite variations of this recipe is everything bagel breakfast casserole. It’s a BIG HIT and consistently gets rave reviews. Or try my different method/recipe for biscuit breakfast casserole with homemade biscuits baked right on top.
Can I Use Potatoes?
Yes, you can replace the bread with diced hash brown potatoes—the kind you find in the freezer section of the grocery store. Guests have *loved* this version. Use about 3 cups (around 380g) of hash browns in place of the bread. You could also peel and dice fresh potatoes, but you’ll need to quickly cook them on the skillet for 10 minutes before using in this dish.
Another wonderful make ahead option with fresh potatoes is this ham and potato casserole that is egg free, but just as delicious.
Do I Have to Use Bread?
Bread or potatoes, yes. Besides eggs, bread is the main ingredient. To avoid a spongey, wet dish, this breakfast casserole needs structure at the bottom. You see, when eggs bake, they release a lot of liquid. Chunks of crusty bread (or hash brown potatoes) soak up some liquid so the casserole is chunky and textured, not flat and wet. It’s almost like the way we need an English muffin with our eggs benedict—to help soak up all that eggy goodness.
If you’re looking for something without this starchy addition, crustless vegetable quiche or an easy frittata are great options.
In Pictures: How to Make Breakfast Casserole
First, place the pieces of bread (or potatoes) in the bottom of a greased 9×13-inch or any 3–4-quart oven-safe dish. I usually use (affiliate links) this glass pan or the pictured red ruffled baking dish, which comes in a set with other sizes—definitely a splurge, but I’ve found the quality to be excellent. Showing you the bread scattered in the pan as well as the optional potato substitution:
Set that aside and pre-cook your vegetables and meat (if the meat is not cooked already). You can do this all in 1 big skillet on the stove, adding onion, garlic, and optional herbs like dried rosemary or your favorite seasoning blend. As that’s sizzling on the stove, whisk the eggs, milk, and cheese together:
Now it’s time to assemble, and I’ve made this process a lot easier over the years. Spoon all of the vegetables/meat mixture on top of the bread. Pour the egg mixture all over that:
Success Tip: Refrigerate Overnight
At this point, you can either bake it right away or refrigerate the casserole overnight and for up to 24 hours. During this time, the flavors mingle together and the bread has a chance to soak up some of the liquid and flavor. Wake up and all you have to do is slide it into the oven. If you’re in a rush, I do recommend at least 30 minutes in the refrigerator before baking, if you can spare it!
Bake until the edges are golden brown. Because it’s so egg heavy, the casserole puffs up in the oven like a cheesecake and then sinks back down as it cools. Cool for 5–10 minutes before slicing and serving.
What to Serve With Breakfast Casserole
For side dishes, fresh fruit and yogurt are light, simple, and quick. For healthy recipe ideas, see my complete list of 30+ healthy breakfast recipes. However, if you’re entertaining—or if you have several hungry teenagers in your house— you’ll love pairing this breakfast casserole with:
- Easy Cinnamon Rolls
- Slow Cooker Cinnamon Rolls
- Maple Chicken Breakfast Sausage
- Pumpkin Cinnamon Rolls or Pumpkin Crumb Cake
- Banana Muffins or Blueberry Muffins
- Baked Oatmeal
- Sour Cream Coffee Cake
- Banana Bread or Zucchini Bread
- Apple Cider French Toast
- Dark Chocolate Raspberry Coffee Cake, a Cinnamon Roll Wreath, or Cranberry Cake (great options around the holidays)
- A Dutch baby piled high with your favorite sweet toppings
- Or any other of my make ahead breakfast ideas!
Your brunch guests will be beyond satisfied. Yes, even the teenagers!
Print
Easy Make-Ahead Breakfast Casserole
- Prep Time: 20 minutes
- Cook Time: 45 minutes
- Total Time: 1 hour, 30 minutes
- Yield: serves 12
- Category: Breakfast
- Method: Cooking
- Cuisine: American
Description
This easy breakfast casserole is infinitely adaptable and you can find variations and suggestions in the recipe Notes below. The version written below with sausage, mushrooms, bell peppers, spinach, and cheddar cheese is generally the most popular with guests. You can assemble the entire dish and refrigerate for up to 24 hours before baking.
Ingredients
- 4 cups (175g or 6 oz) cubes of crusty bread*
- 1 teaspoon olive oil
- 1 pound ground pork sausage, casings removed*
- 1 teaspoon dried rosemary or Italian seasoning, optional
- 3/4 cup (100g) chopped yellow onion (1/2 of a large onion)
- 2 garlic cloves, minced
- 2 cups (275g or 9–10 oz) chopped bell peppers
- 1 cup (100g or 3 oz) sliced mushrooms
- 1 cup roughly chopped fresh spinach
- 12 large eggs
- 1/4 teaspoon salt
- 1/8 teaspoon freshly ground black pepper
- 2/3 cup (160ml) milk or half-and-half*
- 1 cup (100g or 3.5 oz.) shredded cheddar cheese
- optional garnish: green onion and/or chopped parsley
Instructions
- Grease a 9×13-inch or any 3–4-quart oven-safe dish. Arrange bread cubes in an even layer in bottom of pan.
- Heat olive oil in a large skillet over medium heat. Add sausage and rosemary/Italian seasoning, if using, and break up the sausage into bite-size pieces with a wooden spoon or rubber spatula as it begins to cook. Add the onion, garlic, peppers, mushrooms, and spinach and cook until everything has slightly softened and sausage is mostly cooked through, about 5–6 minutes.
- Remove sausage and vegetable mixture from heat and spread in an even layer on top of bread.
- Whisk the eggs, salt, pepper, milk, and cheese together. Evenly pour over sausage/vegetable mixture. Add another sprinkle of salt and pepper on top.
- Cover casserole with plastic wrap or aluminum foil and refrigerate for at least 30 minutes and up to 24 hours. (When ready to bake, allow to sit at room temperature for 10–15 minutes as oven preheats.)
- Preheat the oven to 375°F (191°C). Bake the casserole, uncovered, until the top is golden, edges are crisp, and a toothpick inserted in the center comes out clean, about 40–45 minutes.
- Cool for 10 minutes, then slice and serve.
- Leftovers keep well in the refrigerator for up to 5 days. Reheat in the microwave to your liking.
Notes
- Make Ahead Instructions: This is an excellent make-ahead recipe because you can assemble it before baking up to 24 hours in advance. See step 5. You can also cook the sausage and vegetable mixture up to 24 hours in advance, cover and refrigerate until ready to use.
- Freezing & Reheating Instructions: To freeze, prepare and assemble through step 5, cover with plastic wrap, then a layer of aluminum foil, and freeze for up to 3 months. Thaw overnight in the refrigerator, and then bring to room temperature before baking as directed. You can also freeze the baked casserole for up to 3 months and when doing that, I suggest baking it in a disposable aluminum pan. Cool completely, cover with plastic wrap, then a layer of aluminum foil. When ready to eat, thaw it for about 24 hours (covered) in the refrigerator, remove the plastic wrap layer, then bake in a 350°F (177°C) oven for 25–30 minutes.
- Special Tools (affiliate links): 9×13-inch Baking Dish or any 3–4-quart Oven-Safe Dish | Glass Mixing Bowls | Whisk
- Bread: Crusty sourdough is fantastic in this recipe, or use any crusty, hearty bread. The crustier or more stale, the better. If your bread is fresh and/or flimsy, cut into cubes and bake on a baking sheet in a 300°F (149°C) oven for 10 minutes. It’ll be slightly crisp and ready to use in this recipe. No need to wait for the bread to cool before layering into the baking dish.
- Using Potatoes Instead of Bread: You can replace the bread with diced hash brown potatoes—the kind you find in the freezer section of the grocery store. Use about 3 cups (around 380g) of frozen hash brown potatoes, no need to thaw. You could also peel and dice fresh potatoes, but you’ll need to quickly cook/brown them on a skillet with 1 Tablespoon olive oil over medium heat for 10 minutes before using.
- Sausage or Other Meat: If using pre-cooked sausage links or ham, cut into slices/chunks, and there is no need to cook either. Simply stir into the pre-cooked vegetables before layering into the dish. You can replace the sausage with ground turkey, beef, or chicken—simply pre-cook with the vegetables according to the instructions. If using bacon, I recommend reducing to 1/2 pound and cutting into bite-size pieces. Cook separately from the vegetables until browned. Drain, then mix with the vegetables before layering into the dish.
- Other Vegetables: Feel free to replace all or some of the bell peppers, mushrooms, and spinach with other vegetables such as chopped broccoli, sliced zucchini or squash, or kale. Pre-cook as directed.
- Vegetarian Option: You can leave out the meat and replace with another 1 cup of vegetables.
- Milk: For the richest, heartiest texture, I recommend half-and-half or whole milk. You can use lower-fat milk or dairy-free milk if desired.
- Cheese: I usually use a blend of regular and sharp white cheddar cheeses. Use whatever cheeses you like best, such as pepper jack, feta cheese, Swiss, and/or smoked gouda.
- Half Recipe: You can halve this recipe by halving all of the ingredients and using a 9×9-inch square pan. Bake time is slightly shorter, about 32–36 minutes.
Nutrition
- Serving Size:
- Calories: 212
- Sugar: 3.1 g
- Sodium: 343 mg
- Fat: 12.8 g
- Carbohydrates: 11.2 g
- Protein: 12.5 g
- Cholesterol: 205.4 mg
Reader Comments and Reviews
Unfrozen, the recipe is probably incredibly tasty. However, I would remove the instructions for freezing (or at least the option to freeze unbaked). I made this recipe ahead of time and froze it for 6 days. I baked it the morning I served it and it came out incredibly mushy on the bottom – the bread had soaked up all the moisture and made the bottom half inedible (yes, I used crusty bread). If you’re going to freeze ahead of time, try baking it first instead (but probably shouldn’t be frozen at all for best quality).
Hi Freya, thank you so much for your feedback. We will retest freezing the unbaked casserole and update the make-ahead instructions accordingly. Sorry this recipe didn’t turn out well for you!
Made this yesterday to cook this morning for a house guest from interstate and us. Perfect! 3 clean plates and it went totally to plan. Thank you.
I will be making this for Christmas morning as we did it in the summer for guests and it was an incredible hit. We love it as it is easily a Gluten-Free meal that everyone likes if you use potatoes!
Is one cup of spinach actually enough for this recipe..
Hi Linda, yes, that is what we consistently use in this recipe, but feel free to swap some of the other veggies for more spinach if you wish.
Can you make this without bread or potatoes ( need low carb)
Delicious. Made for our Hospitality Table after our church service. There was nary a crumb left and several asked for the recipe.
While this is certainly “easy” in that the ingredients are standard, it takes forever (for me) to prepare all the veggies. Next time I’ll use prechopped peppers and onions to save time. Personally, I prefer sauteing the sliced mushrooms in butter before adding to the rest of the vegetables.
Do you think this casserole could be made in 2 pie dishes instead of the 9×13 casserole dish? If so, what would the baking time be?
Hi Mary, That should work! We are unsure of the exact bake time but it will be slightly shorter, about 32–36 minutes. Keep an eye on it in the oven!
Hi there, many questions coming lol!
The freezing and reheating instructions suggest using a disposable aluminum pan if baking and then freezing, but not for freezing unbaked. Is there a reason not to use a disposable aluminum pan for the unbaked frozen version? Is there tin flavor transference with liquid egg? Or is it simply the flexibility of the pan that’s an issue with liquid ingredients? If flexibility is the issue, I could transfer it to the bottom of the freezer (and into the oven when thawed) with a cutting board.
Is there a big difference in the finished product with freezing baked or unbaked? Does it get a bit rubbery if it’s baked and frozen and then reheated?
TBH I’m not a huge fan of using aluminum cookware but I would like to make this casserole in advance but I’ll likely be using all my 9×13 pans for Christmas dinner so I won’t want to lose one to the freezer. What about putting a layer or two of parchment paper (including up the sides) into the pan before putting ingredients in? Would this keep the food out of contact with the aluminum? Or is this not recommended for something so liquidy?
Thank you in advance!
Hi Tina, great questions! The main reason I recommend disposable aluminum pans for the baked-then-frozen version (but not the unbaked version) is really about structure and practicality, not safety or flavor. Liquid egg mixtures are heavy and sloshy, and disposable pans can flex when moved, which makes spills and freezer mishaps more likely before baking. There isn’t a concern about tin or aluminum flavor transfer with the eggs. As for texture, freezing unbaked generally gives the best final result: the eggs bake fresh and stay more tender. If you’d rather avoid aluminum altogether, lining a sturdy 9×13 pan with parchment (up the sides) is absolutely fine, even with a liquid mixture. I recommend using 2 overlapping sheets to fully cover the bottom and sides. Once frozen solid, you can lift the casserole out, wrap it well, and return it to the freezer then bake it back in the pan when ready.
Thank you so much Sally for taking the time to answer my many questions! And thats SUCH a great idea about freezing the liquid version till frozen, lifting it out and wrapping and putting back in freezer to free up a pan, so great!
I forgot to cook the frozen potatoes. I put foil over the casserole for 25min. Removed foil and cooked an additional 35min. It turned out wonderful!!! I also made a small dish that was dairy free. It was delicious!! I used unsweetened almond milk and Violife Mexican style shreds.
Omg! I put the frozen potatoes in the casserole dish not realizing I needed to cook them some. I pray this turns out okay. This is my first time making it. I also made a small one for myself with dairy free milk and vegan cheese. I used turkey sausage instead. I will report back if my screw up was not noticed. Fingers crossed
Thanks for giving this casserole a try, Linda! Please do let us know how they turn out!
Can I used packaged fully-cooked chicken sausage, cut up into chunks?
That should work!
This looks SO GOOD. Could I use egg whites instead of whole eggs, or a combination of the two?
Hi Lindy, we haven’t tested this recipe with only egg whites or even a combination. We’re unsure of the exact amount that would be best – it will lose some flavor and richness without the yolks. Let us know if you try it!
But doesn’t the recipe say if opting to use chopped frozen hash browned potatoes,”no need to thaw”?
I understood that part in the recipe said it was only fresh potatoes that would need to be browned/ cooked first, and so Linda’s try shoukd be fire the, right?
Could canned mushrooms be used instead of fresh?
Hi Dora, we haven’t tried that, but don’t see why not. Let us know if you give it a try!
Would frozen tater tots work also work in place of hash brown potatoes?
Hi Jen, I don’t see why not! If you try it, please let us know!
Hi Sally,
The tater tots worked out well.
Thanks!
Can you use gluten-free bread?
We haven’t tested it, but we’re sure you could. The texture may change a bit.
Hi Sally!
I love this recipe! I’ve made it a bunch and it always turns out great! This time I’d like to replace the bread with potatoes. If I slice them thinly and layer them, rather than cube, do you think I can skip the pre-cook step? Let me know what you think!
Hi CuriousCook, I wish we could help, but we haven’t tested that so aren’t sure whether skipping the pre-cook step would be fine in this case. If you try it, please report back and let us know!
Hi!
So I decided to go ahead and layer the sliced potatoes at the bottom of the greased dish, and pre-bake them @400 for 10mins as your recipe suggests. Then covered with the fillings and egg mixture and refrigerated overnight before baking as per the instructions. SO GLAD I followed Sally’s instructions because the potatoes were perfectly tender! Slicing them thin and layering them along the bottom also helped the casserole keep its shape when serving. Everyone loved it!
Another win for Sally’s Baking!
Thanks for your help 🙂
Hi Sally!
I love this recipe and have made it a bunch – it’s always perfect! This time I’d like to use potatoes instead of bread. If I slice them very thin on a mandolin and layer them in the pan, do you think I ca skip the pre-cooking step? I’m wondering if since the potatoes will be thin, they may cook enough in the 40mins in the oven? Let me know what you think!
Hi Curious Cook, we haven’t tried that, so are unsure whether it would work without pre-cooking. If you decide to try it, please report back!
Would this turn out OK if I made it dairy free by using dairy free cheese and an almond milk?
Hi Elizabeth, we haven’t tested those particular substitutions, but let us know if you do. We can’t imagine why it wouldn’t work!
Can I make this using a disposable aluminum pan?
A 9×13 inch disposable aluminum casserole dish works, yes!
Is 6oz of bread really enough? I don’t think 6oz of my sourdough bread equates to anything close to 4 cups. 6oz is only about 1/6 of a loaf.
Hi Rebecca! You can use more bread to get to 4 cups if your bread is on the heavier side.
I have used salad croutons in place of bread. Seasoned or unseasoned.
Made this ahead for camping with a group. The cabin was rustic but had a oven. This was so good! Then we had the leftovers wrapped in a tortilla with taco sauce the next day!
Can you sub diced potatoes instead of the bread?
Hi Dennis, absolutely! See section titled “Can I Use Potatoes?” for more details.
The best savory egg breakfast casserole I’ve ever had! Everyone agrees. I’ve made it for multiple guests many times. I’ve always made the night before, but based on how good leftovers have been, I say you could make ahead and freeze or just reheat. We’ve reheated in the microwave in single servings, and in the same casserole dish in the oven covered with foil. The oven re-heat makes a baked on mess, both methods tasted great. Sometimes it has been a pain to have to prep and make this when overnight guests are in town.
Curious if you know how long this would be okay frozen for? Thinking of making for a Saturday brunch, then the balance pulled out for Christmas morning (Thursday)
Hi Melissa, see Notes after the recipe for freezing and reheating instructions!
Can I use cottage cheese instead of cheddar cheese? Looking to add some extra protein!
This dish is delicious. I took it to church this morning for a breakfast pot luck and most of it was eaten!! I need to know if it freezes well or not.
Hi Linda, absolutely! Check out the recipe notes for freezing and reheating instructions.
Made this today and it was awesome. Used bacon, red&green peppers, onions and a jalapeño for a bit of spice. Three words….Dee-lish-us.
I had to add 3 more eggs because they were small and my pan was a bit bigger. Also used cream which was awesome.
Don’t use the potato hash option as a base everything will come out a big watery mess.
I’ve been making this for at least a dozen years. You can use just about anything, I have even made them sweet ny adding cream cheese and sweetened berries! You have to have the bread, eggs, and either milk or cream. Also, I like it the most when its been refrigerated for at least 10 hours! That way the bread has had time to soak up all of the liquid.
Thank you Sally for reminding me of this great recipe!
I’ve made many of your recipes and not one has failed! I might not like the texture or taste but I always give them a try!
Sally, this recipe MADE my brunch! Thank you for an easy to follow and very adaptable recipe! I used left-over shredded chicken, along with some Mexican chorizo, and my guests could not get enough. This recipe is a keeper and I’m looking forward to making it again and again.
Question- if I use frozen hash browns, can I still assemble that with other ingredients and make it the night before?
Thank you!
Yes, Carrie – enjoy!
made this for father’s day, i used a scale to measure my ingredients. turned out great! i swapped the mushrooms for broccoli. not dense or too dry or liquidy! will definitely make again!! i
This was wonderful, a big hit with my guys from bible study at breakfast.
If using crusty baguette, is it best to cut it up and let ot dry out ahead of time as I would do for bread pudding?
Yes, we would!
This was wonderful, a big hit with my guys from bible study at breakfast.