How to Make a Breakfast Casserole + 9 Recipes

Breakfast casseroles are quite possibly the easiest no-fuss breakfasts on the planet, and we’re simplifying things EVEN more with this guide walking you through how to make them. In this article, you’ll find our very favorite breakfast casseroles, PLUS three simple steps for making your own breakfast casserole without a recipe!

Roasted Veggie Breakfast Casserole

For as customizable and easy as they are to throw together, and how well they save, I give breakfast casseroles the award for tastiest make-ahead breakfast, HANDS-DOWN! These baked beauties can 100% be tailored to your preferences, and are crowd-pleasing enough when you have guests over for the weekend but simple enough to make ahead for a week’s worth of breakfast.

Breakfast Casserole Ingredients

The possibilities are truly ENDLESS when it comes to breakfast casserole ingredients, and to keep things balanced, we typically include a protein, starchy veggie, and several non-starchy veggies in each casserole. We know these ingredients are especially yummy in breakfast casserole (in addition to eggs, of course):

Proteins

Bacon
Breakfast Sausage
Chorizo
Shredded Beef, Chicken, or Pork

Non-Starchy Veggies

Asparagus
Broccoli
Brussels Sprouts
Calabacita Squash
Carrots
Eggplant
Green Beans
Kale
Onions
Peppers (all varieties – bell, hatch, poblano, etc.)
Spinach
Swiss chard
Summer squash
Tomatoes
Zucchini

Starchy Veggies

Butternut Squash
Plantains
Potatoes (all varieties)
Sweet Potatoes

Flavor-Boosters

Cheese (any type of shredded cheese, crumbled feta, or goat cheese)
Pesto (homemade or store-bought)
Seasonings (garlic powder, onion powder, and dried herbs all make great casserole additions!)

How to Make a Breakfast Casserole

Step 1: Pick Your Ingredients

This is a pretty obvious first step! Look in your fridge + freezer to see what you have on hand. Breakfast casseroles are an EXCELLENT way to use up produce that’s on its last leg. Soft bell pepper? Perfect! Wilted kale? That’ll work! It’s also important to note that since your veggies will be chopped and baked, they don’t need to be picture-perfect to make the breakfast casserole cut. Any bruises or imperfections will be hidden post-bake! This is also a great opportunity to use up any leftover protein you may have!

How much should I use?

Remember, this is just a guide! If you have a little more or less than what we recommend, don’t stress…it’s no biggie! Here are some general measurements to help you gauge what you’ll need for your casserole, or how many servings your casserole will make based on what you already have:

SERVES 12

2 dozen eggs
2 pounds of protein
1 1/2 pounds of starchy veggies
2 pounds of non-starchy veggies

SERVES 10

18 eggs
2 pounds of protein
1 pound of starchy veggies
1 1/2 pounds of non-starchy veggies

SERVES 8

12 eggs
1 1/2 pounds of protein
1 pound starchy veggies
1 pound of non-starchy veggies

Roasted Vegetables

Step 2: Prep Your Ingredients

Before putting everything together and popping the assembled casserole into the oven, you’ve got to prep your ingredients. For the veggies + starches, this means giving them a rough chop and a trip into the oven on their own (no one wants a crunchy under-cooked broccoli floret in their breakfast casserole!) and giving the protein a quick cook on the stove-top.

Veggies + starches – rough chop, toss in olive oil, salt, and pepper, and spread out on a rimmed baking sheet to bake in a 400°F oven for 25-35 minutes (until your veggies look nice and wilted).
Proteins – if you aren’t using a leftover, already-cooked protein, you’ll need to give your protein a quick cook on the stovetop. For chorizo and sausage, brown in a pan until crumbled and crispy. If you’re using bacon, fry your desired number of pieces until crisp, and then remove it from the pan and crumble it.
Eggs, seasonings, and other flavor-boosters – in a large bowl, whisk together your eggs (12 does the trick for a large breakfast casserole), seasonings, and any other flavor-boosters you’re using. If you’re including cheese in your breakfast casserole, you can either whisk that in with the eggs OR top your casserole with it right before it heads into the oven – the choice is yours!

Note: if you’re using fresh spinach, we recommend cooking (either steaming or cooking on the stovetop), wringing out the water, and then adding in with the eggs during assembly. For frozen spinach, defrost and wring out the water before adding with the eggs. Any other leafy green can be added with the eggs without being pre-cooked.

Step 3: Assemble + Cook

Grab a deep 9×13 baking dish and add your roasted veggies, starches, and cooked protein to the bottom. Pour your whisked egg mixture over top and, if using, stir in your leafy greens. If you’re topping with cheese, sprinkle it on the casserole, and then pop the whole thing in a 350°F oven for about 30 minutes – you’ll know it’s finished when the center is set and doesn’t jiggle.

Tips for Making Breakfast Casserole

Spread out the veggies. When the veggies go into the oven for the initial roast, spread them out in a single layer. This will help them get nice and roasted without getting soggy or mushy. If you have such an abundance of veggies that you need to roast on two separate sheet pans, consider making two breakfast casseroles! They save REALLY well in the freezer, so none will be wasted! If you’d rather freeze some of your veggies on their own, here’s a great resource for that!
Season well. Seasoning will give your casserole a wonderful boost of flavor, so if you aren’t using something like pesto and are instead relying on dry seasonings, don’t be afraid to add an extra shake or two.
Make-ahead. I’ve said this several times already, but I just can’t emphasize it enough – breakfast casseroles save and reheat SO well. If you’ve got enough time and supplies for more than one, try making a couple at a time. They’ll come in handy when you’re in a pinch!
Top your casserole. Though breakfast casseroles are seriously tasty on their own, don’t be afraid to add sliced avocado, fresh tomato, or a drizzle of hot sauce to your casserole before eating! We’re all about upping the flavor when we can!

How to Save Breakfast Casseroles for Later

You’ve got a couple of options when it comes to saving your breakfast casserole for later. If you’re eating it throughout the week, feel free to cover the whole casserole dish with foil and stick it in the fridge. Alternatively, if you are looking to pre-portion your casserole to take to-go, slice the cooked and cooled casserole into pieces and store in portion-sized storage containers (we like this same-sized glass set). To reheat, just pop a slice in the microwave for 60-90 seconds or reheat for 7-10 minutes in a 350 F oven until fully warmed through.

If you’re looking to make this breakfast to freeze for future enjoyment, we recommend letting your casserole cool slightly before slicing, and then wrapping each individual serving in parchment or wax paper and dropping them into a gallon-sized freezer bag. This way, you can grab out exactly what you need, when you need it, and none of the pieces will be frozen together! When you’re ready to eat, just remove the wrapping from an individual piece and reheat for about 2 minutes in the microwave, or 15 minutes in a 350 F oven until fully warmed through.

Breakfast Casserole vs. Frittata vs. Quiche

Though similar, breakfast casseroles, frittatas, and quiche are not without their differences. Here’s the low-down on all three!

Breakfast Casserole – made up of eggs and veggies (plus any flavor-boosters you choose to add), a breakfast casserole is crustless and baked in the oven.
Frittata – also crustless and made up of eggs, veggies, and flavor-boosters, a frittata is first cooked in a skillet on the stovetop (until the eggs are just set on the bottom) and is then finished off in that same skillet in the oven.
Quiche – typically made in a buttery pie crust, quiche is filled with veggies and an egg + milk (or cream) mixture to form a custard. Quiche is also cooked in the oven but takes a bit longer to cook because of the custard filling.

If you’re looking for a richer breakfast, we recommend going with a quiche. If you’re looking for an everyday egg breakfast, we recommend going with a casserole or frittata. All three save and reheat beautifully!

Our Favorite Breakfast Casseroles

Below are our favorite breakfast casserole, frittata, and quiche recipes!

Paleo Breakfast Casserole

Clean Start Paleo Breakfast Casserole

This casserole offers up healthy starch, protein, and leafy greens! Using both frozen hashed browns and spinach makes this one an absolute breeze to whip up.

Roasted Veggie Breakfast Casserole

Breakfast sausage + veggies roast together to make this beautiful, hearty casserole. This is a tried and true classic and a great one to make first if you’re new to breakfast casseroles!

Chile Relleno Breakfast Casserole

Roasted potatoes, prepared chiles, chorizo, and roasted calabacita squash star in this casserole. This one is bold, flavorful, and a really yummy spin on the more traditional roasted veggie casserole!

Plantain and Sausage Breakfast Casserole