Name: Egg Breakfast Casserole with Sausage and Veggies 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; 12 large eggs; ½ cup milk (120g, any type); ½ cup shredded cheese (56g, any flavor, divided); Olive oil (for sautéing, about 1 tablespoon)

There's something irresistibly comforting about waking up to a warm, hearty breakfast that’s ready to go. This Egg Breakfast Casserole with Sausage and Veggies Recipe is my go-to for busy mornings or weekend brunches — packed with flavor and the kind of cozy goodness that sticks with you all day.

This is a close-up of a baked egg casserole cut into square pieces with one piece being lifted by a silver spatula. The casserole has multiple layers: a golden brown top layer of melted melted cheese with some darker golden spots, underneath is a creamy layer with visible spinach leaves and small red bell pepper pieces. The base layer looks firm and slightly browned. The dish is inside a clear glass baking dish placed on a white marbled surface. The colors are warm with bright orange, green, and red mixed in with the creamy yellow edges. 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 Egg Breakfast Casserole with Sausage and Veggies Recipe
Top Tip
How to Serve Egg Breakfast Casserole with Sausage and Veggies Recipe
Make Ahead and Storage
Frequently Asked Questions:
Final Thoughts
Egg Breakfast Casserole with Sausage and Veggies Recipe

Why You'll Love This Recipe

This egg breakfast casserole has become a staple in my kitchen because it’s so versatile and forgiving. Whether you're feeding family or prepping breakfast for the week, it delivers delicious layers of savory sausage and fresh veggies all bound with fluffy eggs and melty cheese.

Make-Ahead Magic: You can prepare it the night before or even freeze it, making mornings stress-free.
Loaded with Veggies: Fresh spinach, bell peppers, and onions give it a vibrant taste and texture, plus a nutritional boost.
Comfort Food that’s Healthy: High in protein but low in carbs, so you feel full and satisfied without the guilt.
Customizable Flavor: Swap in different cheeses or veggies based on what you have on hand — it always turns out great.

A thick square slice of baked egg casserole with visible layers shows a light yellow base mixed with green spinach pieces, red bell peppers, and melted orange cheese on top. It sits on a white speckled plate, alongside golden-brown roasted potato chunks that have seasoning and small green herbs on them. A silver fork is placed near the egg casserole on the plate. The setting includes a green cloth underneath the plate, with a white marbled surface in the background. Photo taken with an iphone --ar 2:3 --v 7

Ingredients & Why They Work

All the ingredients in this Egg Breakfast Casserole with Sausage and Veggies Recipe play a role in creating a balanced, flavorful meal. From the savory sausage to the hearty veggies and creamy eggs, every bite feels thoughtfully layered. Here’s why I love each component:

Flat lay of raw ground sausage, two peeled garlic cloves, a handful of fresh spinach leaves, two diced red and yellow bell peppers, half a diced yellow onion, a small white bowl of olive oil, twelve large whole eggs with clean shells, a small white bowl of milk, a small white bowl of shredded cheese, and small white bowls of salt and black pepper, all arranged in perfect symmetry 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: It brings savory richness and protein; using a good-quality pork or turkey sausage really ups the flavor.
Olive Oil: Helps sauté veggies gently, adding a hint of fruitiness without overpowering the dish.
Garlic: Just a couple cloves brighten the whole casserole with their aromatic punch.
Fresh Spinach: It wilts down beautifully and keeps the casserole fresh and vibrant.
Bell Peppers: Diced peppers add sweetness and a nice bite — I love using red and yellow for color.
Yellow Onion: Adds subtle sweetness and depth when sautéed.
Eggs: The heart of the casserole, binding everything together with a fluffy texture.
Milk: Keeps the eggs moist and tender; any variety works, even dairy-free options.
Shredded Cheese: Melts into the casserole for gooey, indulgent pockets of flavor — cheddar, mozzarella, or pepper jack are personal favorites.
Salt & Pepper: Essential for bringing out the natural flavors and seasoning the dish perfectly.

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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

I love how flexible this Egg Breakfast Casserole with Sausage and Veggies Recipe is. I often experiment based on what’s in my fridge, and you can too — it welcomes substitutions and tweaks without losing its charm.

Variation: Once, I swapped the sausage for chorizo, which gave the casserole a smoky, spicy kick that my whole family raved about.
Vegetarian Option: Skip the sausage and add mushrooms or even tofu for a meatless yet satisfying version.
Cheese Swap: Try feta or goat cheese for tangy richness that contrasts nicely with the sweet vegetables.
Seasonal Switch: Use whatever veggies you have on hand — zucchini in summer or kale in winter works just as well.

Step-by-Step: How I Make Egg Breakfast Casserole with Sausage and Veggies Recipe

Step 1: Cook the Sausage

Start by spraying your casserole dish with non-stick spray and setting it aside. Heat a skillet over medium heat and brown your sausage, breaking it up into small pieces. I like to let it get just a little crispy around the edges for extra flavor. Even if your sausage is fully cooked, I recommend browning it for that depth of taste.

Step 2: Sauté the Veggies

Using the same skillet (and sausage drippings if you have them), toss in minced garlic, diced peppers, onion, and spinach. Cook until veggies soften and spinach wilts—about 6 to 7 minutes. Season with salt and pepper near the end to avoid drawing out too much moisture upfront.

Step 3: Combine the Layers

Mix the cooked sausage and veggies roughly in the casserole dish, ensuring even distribution so every bite gets some of each. This balance is what makes it so satisfying.

Step 4: Whisk the Eggs & Cheese

In a separate bowl, whisk together eggs, milk, and half of the shredded cheese. Pour this mixture over your sausage and veggies, then sprinkle the remaining cheese on top. Don’t forget an extra pinch of salt and pepper here — seasoning is key!

Step 5: Bake or Refrigerate

You can bake immediately at 375ºF (191ºC) for about 45 minutes, until the edges lightly brown and the center is set. Or, cover tightly with foil or plastic wrap and refrigerate for up to 24 hours — perfect for prepping overnight.

Step 6: Let It Rest and Serve

Once baked, let the casserole cool 15 minutes before slicing. This helps it set, making it easier to serve and enjoy.

Top Tip

From my many breakfasts making this casserole, I learned a few simple tricks that totally elevate the end result. These will help you nail the texture and flavor every single time.

Brown the Sausage Well: Even fully cooked sausage benefits from a quick browning to add color and caramelized flavor.
Don’t Overcrowd the Skillet: When sautéing veggies, keep heat moderate and move them around often to avoid steaming; you want a nice tender-crisp bite.
Use Fresh Eggs & Good Quality Cheese: These simple upgrades make a big difference in taste and creamy texture.
Let It Cool Before Slicing: Gives the casserole time to set up—skip this and it might fall apart on your plate.

How to Serve Egg Breakfast Casserole with Sausage and Veggies Recipe

Egg Breakfast Casserole - Serving Suggestion

Garnishes

I usually top my servings with a sprinkle of chopped fresh parsley or some sliced green onions for a pop of color and freshness. A dollop of sour cream or hot sauce also works wonders if you like a little zing.

Side Dishes

This casserole pairs beautifully with fresh fruit salad for a sweet contrast or crusty toast to scoop up every bit. For a brunch spread, I like serving it alongside crispy roasted potatoes or a light mixed green salad.

Creative Ways to Present

For special occasions, I’ve baked this in individual ramekins to serve personal portions that look fancy but are so easy to make. Another fun idea is to layer it with sliced avocados and cherry tomatoes on top just before serving – it’s a showstopper.

Make Ahead and Storage

Storing Leftovers

I store leftovers tightly covered in the fridge, and they keep well for up to five days. I usually slice the casserole into individual portions right away, so it’s easy to grab and reheat without fuss.

Freezing

Freezing this casserole works like a charm. I freeze it unbaked, tightly wrapped in plastic and foil, for up to two months. When I want it, I thaw overnight in the fridge and then bake fresh — it tastes just as good as the very first time.

Reheating

To reheat, I zap single slices in the microwave for about 1-2 minutes or until warmed through. If I have more time, baking at 350ºF (177ºC) for 15-20 minutes keeps it from drying out and refreshes that just-baked taste.

Frequently Asked Questions:

Can I make this Egg Breakfast Casserole with Sausage and Veggies Recipe ahead of time?

Absolutely! It’s perfect for make-ahead breakfasts. You can assemble it the night before, refrigerate it overnight, and bake it fresh in the morning.

What kind of cheese works best in this casserole?

I recommend using cheeses that melt well like cheddar, mozzarella, or pepper jack. But feel free to experiment with gouda, Monterey Jack, or even a sprinkle of feta for a different flavor profile.

Can I freeze this casserole?

Yes! You can freeze the casserole unbaked for up to two months. Just wrap it tightly in plastic wrap and foil. Thaw overnight in the fridge before baking as usual.

How do I know when the casserole is done baking?

The casserole is done when the edges are golden brown and the center is set (not jiggly). Usually, this takes about 45 minutes at 375ºF (191ºC).

Final Thoughts

This Egg Breakfast Casserole with Sausage and Veggies Recipe holds a special place in my heart because it makes mornings so much simpler without skimping on taste or nourishment. I hope you find yourself reaching for it on busy days or lazy weekends, savoring every comforting bite — just like I do.