This breakfast casserole recipe is perfect for feeding a crowd. Filled with eggs, cheese, and veggies, it’s hearty, delicious, and easy to make ahead!
This breakfast casserole recipe is hearty and flavorful, filled with eggs, cheese, potatoes, and vegetables. I love to make it when I host family or friends for brunch. It feeds a crowd, it’s easy to make ahead, and it’s always a hit.
I adapted this easy breakfast casserole recipe from my mom’s. She’s been making her egg breakfast casserole on Easter and Christmas morning for as long as I can remember. This version incorporates a few extra veggies but otherwise sticks to my mom’s tried-and-true recipe. Here’s why I love it:
You can make it ahead. Assemble the night before and bake the next day, or fully bake the casserole ahead of time. Find detailed make-ahead instructions below!
It’s simple to throw together. This recipe calls for basic equipment and ingredients.
You can adapt it to use different cheeses or vegetables. Feel free to swap in your favorites!
Try it for your next holiday brunch, or make it on any weekend morning. Bonus: Leftovers (if you have any) will reheat perfectly for breakfast throughout the week!
What’s In This Easy Breakfast Casserole
This breakfast casserole recipe has 4 main parts:
Potatoes – Roasted with olive oil, salt, and pepper, they create a starchy, satisfying layer at the bottom of the casserole.
Sautéed veggies – Yellow onion, garlic, bell peppers, spinach, and green onions add vibrant color and savory flavor to the casserole.
Cheddar cheese – It adds richness and salty, nutty flavor.
The egg mixture – I whisk the eggs with milk so that they have a delicate, fluffy texture when baked. Use any type you like. I’ve successfully made this recipe with whole milk and unsweetened almond milk.
Find the complete recipe with measurements below.
Recipe Variations
Like my frittata recipe or crustless quiche, this breakfast casserole is adaptable! Here are a few ways to change it up:
Vary the veggies. Sautéed broccoli, mushrooms, asparagus, or zucchini are all great in this recipe.
Change the cheese. Pepper jack cheese is a fun replacement for the shredded cheddar. A mix of cheeses works too!
Switch to sweet potatoes. They’re just as good as regular ones in this hearty breakfast casserole.
Or use hash browns. I’ve had great results using diced frozen hash browns instead of the potatoes. See the recipe notes for instructions on making this swap!
How to Make Breakfast Casserole
You can find the complete recipe with measurements at the bottom of this post, but for now, here’s an overview of how it goes:
First, roast the potatoes. Chop them into 1/4-inch cubes. Note: This is small! Smaller cubes=more crisp, golden brown edges. Be careful not to cut them too large.
Place the potatoes on a parchment-lined baking sheet, and toss with olive oil, salt, and pepper. Roast at 425°F for 20 to 25 minutes, or until tender and browned.
Meanwhile, prep the egg mixture. Whisk together the eggs, milk, and 1/4 teaspoon salt in a large bowl.
Next, cook the veggies. Sauté the onion until soft, and then stir in the peppers and garlic. Cook for 2 minutes before adding the spinach and half the green onion. Cook until the spinach is just wilted.
Then, assemble the casserole. Spread the roasted potatoes at the bottom of an oiled 9×13-inch baking dish. Top with two-thirds of the shredded cheese, followed by the sautéed veggies.
Pour in the egg mixture. Finally, sprinkle the remaining cheese and reserved green onion on top.
Bake the casserole at 350°F until set, 40 to 45 minutes. Let stand for 5 minutes before slicing and serving. Enjoy!
Make-Ahead Breakfast Casserole
One of my favorite things about this egg casserole recipe is that you can make it ahead.
Here are two options for prepping it in advance:
Assemble the casserole the night before. Layer the potatoes, vegetables, cheese, and eggs in the pan, and tightly cover with foil or plastic wrap. Refrigerate overnight. The next morning, uncover and let sit at room temperature while you preheat the oven. Then, bake according to the recipe.
Cook the components the day before and assemble in the morning. Roast the potatoes and sauté the veggies a day ahead, and store them in airtight containers in the fridge. With these components prepped, the egg casserole is quick and easy to assemble day-of.
Storing and Reheating Leftovers
Leftover breakfast casserole keeps well in an airtight container in the refrigerator for up to 5 days. It reheats perfectly in the microwave or a 350°F oven.
You can also freeze this breakfast casserole. Wrap slices tightly in aluminum foil or plastic wrap, or seal them in an airtight container. Freeze for up to 3 months. Allow to thaw overnight in the fridge before reheating.
What to Serve with Breakfast Casserole
Enjoy this recipe on its own for a satisfying breakfast. Or, for a larger brunch, pair it with fresh fruit and/or any of these sweet breakfast recipes:
Looking for more brunch ideas? Check out these 51 Best Brunch Recipes!
Breakfast Casserole
Serves 12
This easy breakfast casserole recipe is perfect for feeding a crowd! It’s hearty and flavorful, filled with roasted potatoes, veggies, eggs, and cheddar cheese. Find make-ahead instructions in the blog post above.
For the casserole
12 large eggs1 cup milk1¼ teaspoons sea salt2 tablespoons extra-virgin olive oil, plus more for the baking dish½ medium yellow onion, choppedFreshly ground black pepper2 garlic cloves, chopped1 red bell pepper, stemmed, seeded, and chopped1 green bell pepper, stemmed, seeded, and chopped1 cup fresh spinach, roughly chopped4 green onions, chopped1½ cups shredded cheddar cheese
Cook ModePrevent your screen from going dark
Roast the potatoes: Preheat the oven to 425°F and line a baking sheet with parchment paper. Place the potatoes on the baking sheet. Drizzle with the olive oil and sprinkle with the salt and several grinds of pepper. Toss to coat. Spread evenly on the baking sheet and roast for 20 to 25 minutes, or until tender and browned.
Make the casserole: Reduce the oven temperature to 350°F and oil a 9×13-inch baking dish.
In a large bowl, whisk together the eggs, milk, and ¼ teaspoon of the salt. Set aside.
Heat the olive oil in a large skillet over medium heat. Add the onion, the remaining 1 teaspoon salt, and several grinds of pepper. Cook, stirring occasionally, for 5 to 8 minutes, or until soft. Add the garlic, red pepper, and green pepper and cook, stirring occasionally, for 2 minutes. Add the spinach and half the green onions and toss until the spinach is just wilted.
Spread the potatoes in an even layer in the prepared baking dish. Top with 1 cup of the cheese, followed by the sautéed veggies. Pour in the egg mixture and sprinkle with the remaining ½ cup cheese and the reserved green onions.
Bake for 40 to 45 minutes, or until the eggs are set.
Let stand for 5 minutes before slicing and serving.
*Using frozen hash browns: To simplify this recipe, you can use 1 pound diced frozen hash brown potatoes instead of the roasted potatoes. Let thaw before adding to the casserole. When I use hash browns, I typically need to bake the casserole a few minutes longer for it to set.
