Make Ahead Breakfast Casserole For A Crowd

Name: Make Ahead Breakfast Casserole For A Crowd
Prep time: 20 min
Cook time: 40 min
Total time: 1 h
Yield: 12 servings
Ingredients: 12 large eggs; 2 cups milk; 1 teaspoon salt; 1/2 teaspoon black pepper; 1 teaspoon garlic powder; 1 teaspoon onion powder; 1 cup cooked sausage, crumbled; 1 cup diced bell peppers; 1 cup diced onions; 2 cups shredded cheddar cheese; 1 teaspoon chopped fresh parsley (optional)

Highlighted under: Comfort Kitchen Creations

I love starting my day with a hearty breakfast, and this Make Ahead Breakfast Casserole for a Crowd is my go-to dish for gatherings. It's simple to prepare and can be made the night before, which means less stress in the morning. The combination of eggs, cheese, and savory vegetables creates a comforting dish that everyone will enjoy. Plus, it's perfect for feeding a large group without spending hours in the kitchen, making it ideal for brunch parties or family holidays.

Created by

Maisie Clarke

Last updated on 2026-03-05T05:37:53.807Z

When I first tried making a casserole for breakfast, I was amazed at how easy it was to combine my favorite ingredients into a single dish. The make-ahead aspect truly saved me during a busy holiday breakfast with friends. I learned that allowing the casserole to sit overnight lets the flavors meld beautifully, ensuring each bite is packed with deliciousness.

To elevate the dish, I like to experiment with different cheese combinations and veggies based on what I have on hand. Using fresh herbs, like chives or parsley, adds a burst of flavor and freshness that keeps the casserole exciting. It’s a perfect way to use leftover vegetables while offering something everyone will love!

Why You'll Love This Recipe
Easy to prepare ahead of time for stress-free mornings
Customize with your favorite vegetables and cheeses
Hearty and filling, perfect for feeding large groups
Great for any occasion, from family brunches to holiday gatherings

Understanding the Ingredients

The foundation of this breakfast casserole is the combination of eggs and milk, which creates a custardy texture. Using large eggs ensures the dish has sufficient structure and richness. If you're aiming for a lighter version, consider substituting half of the milk with a plant-based alternative, such as almond milk. Just make sure the chosen substitute is unsweetened to avoid altering the dish's flavor.

The addition of cooked sausage adds a savory depth and protein punch to every bite. You can easily swap in cooked bacon, diced ham, or a vegetarian sausage for a different flavor profile. It's essential to ensure the meat is fully cooked and crumbled to avoid large clumps that might disrupt the casserole's texture during baking.

Techniques for Perfecting Your Casserole

When whisking the egg mixture, aim for a uniform color and slight frothiness, which indicates thorough incorporation of the ingredients. This step is crucial for a consistent texture throughout the casserole. A hand whisk is perfect for this, but an electric mixer can save time and effort, especially if you're preparing a double batch.

Covering the casserole with foil while it chills in the refrigerator helps preserve moisture and allows the flavors to meld beautifully. Be sure not to skip this step, as it prevents the top from becoming dry while baking. When ready to bake, removing the foil enhances browning, leading to a golden, appetizing finish.

Ingredients

Breakfast Casserole Ingredients

12 large eggs
2 cups milk
1 teaspoon salt
1/2 teaspoon black pepper
1 teaspoon garlic powder
1 teaspoon onion powder
1 cup cooked sausage, crumbled
1 cup diced bell peppers
1 cup diced onions
2 cups shredded cheddar cheese
1 teaspoon chopped fresh parsley (optional)

Instructions

Prepare the Casserole Base

In a large mixing bowl, whisk together the eggs, milk, salt, pepper, garlic powder, and onion powder until well combined.

Add Fillings

Stir in the cooked sausage, diced bell peppers, diced onions, and shredded cheese until evenly distributed.

Transfer to Baking Dish

Pour the mixture into a greased 9x13 inch baking dish, spread evenly, and cover with aluminum foil.

Chill Overnight

Refrigerate the casserole for at least 4 hours, or overnight if possible, to allow flavors to meld.

Bake the Casserole

Preheat the oven to 350°F (175°C). Remove the foil and bake for 40-45 minutes, or until the center is set and edges are lightly browned.

Serve and Enjoy

Let the casserole cool for a few minutes before slicing into squares. Garnish with fresh parsley if desired and serve warm.

Pro Tips

For added flavor, try mixing in some cooked bacon or different herbs. You can also make this vegetarian by omitting the sausage and adding extra vegetables. If you prefer a crispy top, broil the casserole for an additional 2-3 minutes at the end!

Make-Ahead and Storage Tips

This casserole can be assembled up to 24 hours in advance, making it a great option for busy mornings. Once you've poured the mixture into the baking dish, simply cover it tightly with plastic wrap or foil and store it in the refrigerator. This allows the bread and vegetables to soak up the egg mixture, leading to an even more delicious product when baked.

After baking, if you have leftovers, allow the casserole to cool completely before storing it in an airtight container. It can be kept in the refrigerator for about 3-4 days. To enjoy it later, simply reheat in the oven at 350°F (175°C) for about 20-30 minutes until warmed through, or microwave individual portions for a quick breakfast.

Serving Suggestions and Variations

For an extra touch of flavor, consider serving the casserole with a side of salsa or a dollop of sour cream. Fresh avocado slices or a simple green salad can also add a refreshing contrast. Additionally, you might sprinkle some hot sauce on top for those who enjoy a bit of heat.

Feel free to experiment with the vegetable mix—zucchini, spinach, or mushrooms also work beautifully in this casserole. If you're looking for a more gourmet twist, try adding feta cheese or sun-dried tomatoes. Just keep the total amount of fillings equal to ensure the casserole sets correctly.

Questions About Recipes

→ Can I make this casserole the night before?

Yes! In fact, it’s recommended to let it sit overnight to enhance the flavors.

→ What other vegetables can I add?

Feel free to add spinach, mushrooms, or zucchini for a nutritional boost!

→ Can I freeze leftovers?

Yes, it freezes well! Just make sure it's fully cooled before freezing, and reheat thoroughly when ready to serve.

→ How long can I store leftovers in the fridge?

Leftovers can be refrigerated for up to 3-4 days. Just reheat in the oven or microwave before serving.