Name: Easy Sausage Breakfast Egg Casserole Recipe
Prep time: 20 min
Cook time: 45 min
Total time: 1 h 5 min
Cuisine: American
Ingredients: 10 to 12 ounces sausage (casing removed); 2 cloves garlic (minced); 3 cups fresh spinach (90g); 2 large bell peppers (diced); ½ medium yellow onion (diced); Salt and pepper (to taste); Olive oil (for sautéing); 12 large eggs; ½ cup milk (120g; any type); ½ cup shredded cheese (56g; any flavor, divided)

There’s nothing quite like the aroma of a hearty breakfast baking away on a cozy morning, and this Easy Sausage Breakfast Egg Casserole Recipe brings that warmth right to your table. It’s simple, packed with flavor, and honestly, just pure comfort in every bite.

The image shows a close-up of a rectangular baked dish divided into square pieces with one piece being lifted by a silver spatula. The dish has about four visible layers: the bottom layer is light and slightly crusty, the second layer is a mix of red and green bits suggesting chopped peppers and spinach, the third layer is creamy white, likely cheese or eggs, and the top layer is a golden orange melted cheese with browned spots and scattered dark green leafy bits. The baking dish is transparent glass placed on a white marbled surface. photo taken with an iphone --ar 2:3 --v 7

Jump to:

Why You'll Love This Recipe
Ingredients & Why They Work
Make It Your Way
Step-by-Step: How I Make Easy Sausage Breakfast Egg Casserole Recipe
Top Tip
How to Serve Easy Sausage Breakfast Egg Casserole Recipe
Make Ahead and Storage
Frequently Asked Questions:
Final Thoughts
Easy Sausage Breakfast Egg Casserole Recipe

Why You'll Love This Recipe

I love sharing this casserole because it’s one of those dishes that feel fancy without any fuss. It’s great for busy mornings, brunches with friends, or even prepping ahead for the week—giving you a breakfast win every time.

Simple Prep: You only need a handful of ingredients and a baking dish, so it’s super beginner-friendly.
Make-Ahead Friendly: Prep it the night before or even freeze it for later; it still turns out delicious every time.
Customizable: You can swap veggies, cheese, or sausage types to fit your taste or pantry.
Feeds a Crowd: This recipe yields about 10 servings—perfect for weekend brunch or family gatherings.

This image shows a white speckled plate holding a square piece of egg casserole with three visible layers: the top layer is golden and melted cheese mixed with bits of green spinach and red peppers, the middle layer is creamy and light yellow with visible spinach and small red vegetable pieces, and the bottom layer contains cooked pieces of light brown potatoes and some egg mixture. Next to the casserole on the plate are roasted potato chunks that are golden brown and crisp. A silver fork rests on the edge of the plate. The plate sits on a white marbled surface with a dark green cloth partly visible underneath. Photo taken with an iphone --ar 2:3 --v 7

Ingredients & Why They Work

Each ingredient in this casserole has a purpose that builds flavors and textures beautifully. From savory sausage to fresh veggies, here’s what you need and why it shines in this recipe.

Flat lay of raw ground sausage in a mound, two cloves of peeled garlic, a small white bowl of olive oil, a handful of fresh green spinach leaves, two large diced red and yellow bell peppers mixed together, half of a medium yellow onion diced, a dozen whole large brown eggs with clean uncracked shells, a small white bowl filled with fresh milk, a small white bowl containing shredded cheese, a white ceramic bowl with mixed salt and black peppercorns placed symmetrically, all ingredients arranged neatly in perfect balance and symmetry, placed on a clean white marble surface, soft natural light, photo taken with an iPhone, professional food photography style, fresh ingredients, white ceramic bowls, no bottles, no duplicates, no utensils, no packaging --ar 2:3 --v 7 --p m7354615311229779997

Sausage: Adds rich, meaty flavor and a bit of fat for moisture; I recommend using your favorite breakfast sausage, casing removed.
Olive oil: Helps sauté the veggies and garlic without sticking—adds a subtle richness.
Garlic: Just two cloves bring a warm, aromatic base to the veggies.
Fresh spinach: Adds color, nutrition, and a mild earthiness that balances the richer ingredients.
Bell peppers: Diced for sweetness and crunch, they brighten up the casserole.
Yellow onion: Gives a gentle savory depth when softened with the veggies.
Salt and pepper: Essential for seasoning; adjust as you go for the best flavor.
Large eggs: The star binder that holds everything together, providing protein and structure.
Milk: Keeps the eggs tender and adds a creamy texture—any kind works.
Shredded cheese: I use half before baking and half on top for melty, golden goodness.

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Note: You'll find the complete list of ingredients, along with their exact measurements, in the printable recipe card at the bottom of this post.

Make It Your Way

One of the best things about this Easy Sausage Breakfast Egg Casserole Recipe is how easy it is to tweak. I’ve tried swapping out veggies or cheese depending on what’s in season or what’s left in my fridge.

Variation: Sometimes I swap the spinach for kale or add mushrooms for extra heartiness—it always works well.
Dairy-Free: Use almond or oat milk and skip the cheese, or try a plant-based cheese for a tasty dairy-free option.
Vegetarian: Replace sausage with sautéed mushrooms or vegetarian sausage for a meaty texture without the meat.
Spicy Kick: Add some diced jalapeño or a pinch of cayenne pepper when cooking the veggies for a little heat.

Step-by-Step: How I Make Easy Sausage Breakfast Egg Casserole Recipe

Step 1: Prep Your Dish & Brown the Sausage

Start by spraying your casserole dish with non-stick spray; I like a 7 x 11 or 9 x 13 inch dish. If you’re baking immediately, preheat your oven to 375°F (191°C). Next, brown the sausage in a skillet over medium heat. Even if your sausage is pre-cooked, I recommend browning it just a bit for extra flavor and texture—don’t rush, let it develop those nice golden bits.

Step 2: Sauté Your Veggies

Using the same skillet (with some sausage grease or a splash of olive oil), sauté your minced garlic, fresh spinach, diced bell peppers, and diced yellow onion. Cook until veggies are tender and spinach is fully wilted—about 6 to 7 minutes. Season with salt and pepper near the end to bring out the flavors.

Step 3: Combine Sausage and Veggies in Casserole Dish

Transfer the cooked veggies to the browned sausage in your casserole dish and gently stir to mix them evenly. This ensures every bite is packed with that delicious combo.

Step 4: Whisk Eggs, Milk, and Cheese

In a separate bowl, whisk together the eggs, milk, and half the shredded cheese. Whisk until the mixture is smooth and a little frothy—that airiness helps create a fluffy bake.

Step 5: Pour Egg Mixture and Bake

Pour the egg mixture evenly over the sausage and veggies in the casserole dish. Sprinkle the remaining cheese on top, then add a light sprinkle of salt and pepper. It’s ready to bake! Put it in the 375°F (191°C) oven for about 45 minutes, or until the edges start to brown and the center is set. Give it at least 15 minutes to cool before serving.

Top Tip

I’ve made this casserole dozens of times, and a few tricks have made all the difference to the texture and flavor every time. Here are the top tips I swear by for your success.

Don’t Overcrowd the Pan: When browning the sausage, give it space to brown nicely instead of steaming in a tight pan.
Veggie Timing: Sauté the vegetables until tender but not mushy—this keeps the casserole from getting soggy.
Cheese Distribution: Splitting the cheese between the mix and topping adds great cheesy layers and a golden crust.
Let It Rest: Waiting 15 minutes after baking makes slicing easier and helps ingredients settle for better flavor.

How to Serve Easy Sausage Breakfast Egg Casserole Recipe

Sausage Breakfast Casserole - Serving Suggestion

Garnishes

I like to add a sprinkle of fresh parsley or chopped chives on top for a pop of color and freshness. Sometimes a dollop of sour cream or a few slices of avocado works beautifully, especially if you want something creamy alongside.

Side Dishes

This casserole pairs wonderfully with fresh fruit salad or crispy roasted potatoes. For a weekend brunch, some toasted artisan bread or buttery croissants elevate the meal nicely.

Creative Ways to Present

One time, I made this for a holiday brunch and topped individual servings with a little tomato salsa and sliced jalapeños for a colorful, festive feel. You can even portion it into mini muffin tins for bite-sized servings that look adorable on a brunch spread.

Make Ahead and Storage

Storing Leftovers

I usually store leftovers in an airtight container in the refrigerator. They keep well for up to five days, making it perfect for quick breakfasts during the week. Just reheat as needed.

Freezing

This casserole freezes surprisingly well. I recommend freezing it unbaked, tightly wrapped in plastic and foil, so you can take it out, thaw overnight in the fridge, then bake fresh when you want. It’s a lifesaver for meal prep and busy mornings.

Reheating

For reheating, I pop individual servings into the microwave for about one to two minutes. For larger portions, reheat in the oven at 350°F (177°C) for about 15-20 minutes to keep it from drying out.

Frequently Asked Questions:

Can I make this Easy Sausage Breakfast Egg Casserole Recipe vegetarian?

Yes! Simply swap out the sausage for plant-based sausage or sautéed mushrooms to keep that meaty texture and depth of flavor. The veggies and eggs will still provide plenty of heartiness.

How far in advance can I prepare this casserole?

You can prepare the casserole up to 24 hours ahead and keep it refrigerated before baking. You can also freeze it unbaked for up to two months, which makes it great for meal prepping.

What type of cheese works best?

Any shredded cheese melts well in this casserole. I usually go with sharp cheddar for its flavor but have also enjoyed mozzarella, pepper jack for a kick, or even a blend. Feel free to choose what you love or have on hand.

Can I use different vegetables in the casserole?

Absolutely! This recipe is very flexible. Try kale, mushrooms, zucchini, or even broccoli. Just sauté your chosen veggies until tender to avoid excess moisture in the casserole.

Final Thoughts

This Easy Sausage Breakfast Egg Casserole Recipe has become a staple at my house because it’s straightforward, forgiving, and always satisfying. Whether you’re feeding a crowd or just want a comforting breakfast that lasts all week, this casserole ticks every box. I can’t wait for you to try it—and maybe even put your own spin on it!