Breakfast Casserole Recipe with Eggs, Sausage and Cheese

Breakfast casserole is a baked egg dish loaded with beef sausage, cheddar cheese, colorful bell peppers, and a creamy egg custard that sets into perfect, sliceable squares. With just 10 minutes of prep and one baking dish to clean, this recipe is the most practical, satisfying breakfast for a crowd you can put on the table, and it works just as well as a make-ahead breakfast casserole for Christmas morning or any busy weekend.

Detail	Info
Prep Time	10 minutes
Cook Time	55 minutes
Total Time	1 hour 5 minutes
Servings	12
Difficulty	Easy
Cuisine	American

Table of Contents

Breakfast Casserole Recipe Contents

This is my absolute go-to recipe whenever I need to feed a crowd without spending the morning chained to a stovetop. Over the years of making this casserole, I have tested it with a handful of different egg-to-dairy ratios, and the combination of sour cream plus a splash of milk gives the final bake an incredibly rich, custardy texture that plain egg mixtures just cannot match.

My best family always asks for this one on Christmas morning, New Year’s Day, and honestly any Sunday that calls for something special. The secret that changed everything for me: drain that beef sausage grease thoroughly before adding it to the egg mixture.

Even a tablespoon of leftover fat will make the finished casserole greasy at the bottom, which ruins an otherwise outstanding dish.

My second pro tip is to mix the egg base on the lowest speed of your electric mixer, and stop the moment everything is combined.

Over-beating the eggs whips too much air in and the casserole can puff up dramatically in the oven then collapse as it cools, leaving a dense, rubbery layer. Gentle mixing means a tender, cohesive slice every time.

If you are planning this as a make-ahead casserole for a special morning, assemble everything the night before, cover the dish tightly, and refrigerate it overnight, then bake straight from the fridge with an extra 5 to 10 minutes added to the cook time.

Why This Breakfast Casserole Recipe Works Every Time

The reason this is genuinely the best breakfast casserole comes down to the egg custard base. Using sour cream instead of straight milk creates a denser, more satisfying set that slices cleanly rather than crumbling apart on the spatula. The fat in the sour cream also coats the proteins in the eggs, slowing them down slightly during baking so the casserole stays tender rather than turning rubbery at the edges while the center is still wet.

Sautéing the bell peppers and green onions separately, rather than adding them raw, makes a meaningful difference. Raw vegetables release moisture as they bake, which steams the egg mixture from the inside and can leave the center wet long after the edges are done. A quick 2-to-3-minute sauté drives off that excess moisture and lets the vegetables pick up a little color, which deepens the overall savory flavor of the finished dish. If you enjoy other hearty baked casserole dinners, you already know that properly prepared vegetables are always what separates a good bake from a great one.

Finally, the 2 pounds of beef sausage is not excessive for 12 servings. Each square of this savory breakfast casserole contains a full, satisfying portion of protein, which means this dish genuinely holds people over until lunch. There are no filler ingredients, no bread base, and no potato layer competing for space. Every bite delivers beef, egg, cheese, and vegetable in the right proportion.

The Best Breakfast Casserole Ingredients

Ingredient	Quantity	Notes and Alternatives
Beef sausage	2 pounds (900g)	Use ground beef sausage, sliced beef kielbasa, or turkey sausage for a leaner option
Eggs	12 large	Large eggs work best; medium eggs will produce a slightly thinner custard
Sour cream	1 cup (240g)	Light or full-fat both work; full-fat gives a richer result. Plain Greek yogurt is a reliable substitute
Milk	1/4 cup (60ml)	Whole milk preferred; 2% works fine. Unsweetened oat milk for a dairy-reduced version
Kosher salt	1 teaspoon	Reduce to 3/4 tsp if your sausage is heavily seasoned
Ground black pepper	1/2 teaspoon	Freshly cracked preferred for a stronger flavor
Green onions	4 stalks	White and light green parts sliced thin; substitute 1/4 cup diced yellow onion
Green bell pepper	1/2 medium, diced	Any color works; orange or yellow bell pepper adds a milder, sweeter note
Red bell pepper	1/2 medium, diced	Adds color and a touch of sweetness; jarred roasted red pepper works in a pinch
Shredded cheddar cheese	2 cups (200g)	Sharp cheddar gives the most flavor; Colby-Jack or Monterey Jack are milder alternatives

Mise en Place and Prep Steps

1. Preheat the oven to 350°F (175°C) so it reaches full temperature before the casserole goes in.
2. Spray a 9×13-inch baking dish generously with cooking spray and set it on the counter within reach.
3. Dice the green and red bell peppers into roughly 1/2-inch pieces and place them in a small bowl together.
4. Slice the green onions thin, both the white and light green parts, and add them to the bowl with the bell peppers.
5. Measure out the sour cream and milk and place them beside the mixing bowl.
6. Shred the cheddar cheese if starting from a block, or measure pre-shredded cheese. Set aside 1/4 cup to sprinkle on top if desired.
7. Crack all 12 eggs into the large mixing bowl, checking for shell fragments, and set the bowl aside ready for mixing.

How To Make Breakfast Casserole Step-by-Step

Step 1: Build the Egg Base

1. Add eggs, sour cream, milk, shredded cheddar cheese, salt, and pepper to a large mixing bowl.
2. Mix on low speed with electric hand mixers for 15 to 20 seconds, stopping the moment the mixture is combined and uniform. Do not overmix.

Step 2: Cook the Sausage

3. Heat a large skillet over medium heat until the pan is hot but not smoking.
4. Add the beef sausage and cook for 7 to 9 minutes, breaking it into small crumbles with a wooden spoon as it browns.
5. Drain the skillet thoroughly, leaving just a very thin film of fat in the pan, and transfer the cooked sausage into the egg mixture bowl.

Step 3: Sauté the Vegetables

6. Return the skillet to medium heat. Add the diced bell peppers and sliced green onions directly to the pan without adding any oil.
7. Sauté for 2 to 3 minutes, stirring occasionally, until the vegetables are slightly softened and any surface moisture has cooked off.
8. Transfer the sautéed vegetables into the bowl with the egg and sausage mixture.

Step 4: Assemble and Bake

9. Stir the entire mixture together with a large spoon until the sausage and vegetables are evenly distributed throughout the egg base.
10. Pour the mixture into the prepared 9×13-inch baking dish, spreading it to the corners.
11. Bake on the center oven rack for 35 to 50 minutes, checking at the 35-minute mark. The casserole is done when the edges are fully set and the center has only a slight jiggle when the pan is gently nudged.
12. Remove from the oven and allow to rest for 5 minutes before slicing into 12 squares and serving.

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Chef Tips for a Perfect Breakfast Casserole

• Drain the sausage thoroughly. Excess grease pooling at the bottom of the dish is the single most common reason a savory breakfast casserole turns out greasy and dense. After browning, tip the skillet and spoon out the fat, or transfer the sausage to a plate lined with paper towels for 60 seconds before adding it to the eggs.
• Mix the egg base on low, briefly. Stop the mixer the moment you see a uniform, pale yellow mixture. Overworked eggs trap too much air, causing the casserole to puff dramatically then fall and turn rubbery as it cools.
• Check for doneness with a gentle shake, not a knife. Insert a knife only if you are unsure, a clean pull with a slight custardy coating is exactly right. A completely dry knife often means the casserole has gone 5 to 8 minutes past its ideal point.
• Use a metal or ceramic pan, not glass. Glass baking dishes conduct heat unevenly and can leave the bottom of the casserole pale and underdone while the top browns. A ceramic or light metal 9×13 pan gives a more even, golden result.
• Finish with a cheese sprinkle in the last 10 minutes. For a deeper, more attractive cheddar crust on top, hold back 1/4 cup of the shredded cheese and scatter it over the casserole at the 30-minute mark. It will melt and brown into a beautiful golden layer.
• Let it rest before cutting. The egg custard continues to set for the first 4 to 5 minutes out of the oven. Cutting immediately causes the squares to fall apart and lose their shape on the plate.

Common Mistakes to Avoid When Making Breakfast Casserole

Mistake	Why It Happens	How to Fix It
Wet, soggy center	Raw vegetables release moisture during baking, creating steam pockets inside the custard	Always sauté vegetables for 2 to 3 minutes before adding to the egg base to drive off excess moisture
Greasy bottom layer	Insufficient draining of the sausage grease after browning	Drain the skillet completely after cooking the sausage, blotting with paper towels if needed
Rubbery, dense texture	Overmixing the egg base incorporates too much air, which collapses during baking	Mix on the lowest speed for no more than 20 seconds and stop immediately when combined
Uneven bake (edges set, center still liquid)	Oven temperature too high or casserole placed on the top rack	Always bake on the center rack at exactly 350°F and start checking at the 35-minute mark
Casserole falls apart when sliced	Cutting immediately after removing from the oven before the custard finishes setting	Rest the casserole uncovered on the counter for a full 5 minutes before slicing

Variations and Substitutions for Every Breakfast Casserole Idea

One of the greatest strengths of this recipe is how easily it adapts to different tastes and dietary needs. These are the tested substitutions that work without changing the baking time or the overall structure of the dish. If you love experimenting with baked casserole dishes with bold flavors, this framework opens up a huge range of breakfast casserole ideas.

Ingredient	Substitution	Impact on Flavor
Beef sausage	Turkey sausage or chicken sausage	Leaner, slightly milder flavor with the same savory profile
Sour cream	Plain full-fat Greek yogurt	Slightly tangier and higher in protein; texture is nearly identical
Cheddar cheese	Colby-Jack or Pepper Jack	Milder or spicier depending on the choice; both melt well
Bell peppers	Diced zucchini or mushrooms	Earthier flavor; mushrooms add an umami depth that complements the beef sausage
Whole milk	Unsweetened oat milk or almond milk	Slightly thinner custard; flavor difference is minimal after baking
Green onions	1/4 cup diced yellow onion, sautéed	Stronger, more pronounced onion flavor throughout the dish

Serving Suggestions and Pairings for a Crowd

This breakfast casserole is a complete meal on its own, but pairing it thoughtfully turns a simple breakfast into a full spread. For a Christmas morning breakfast for a crowd, serve squares alongside a fruit salad of fresh berries, sliced melon, and citrus segments to balance the richness of the egg and cheese. A side of warm, buttered toast or sliced crusty bread lets guests mop up any extra egg from the plate.

For a weekend brunch setting, add a simple green salad dressed with a light vinaigrette and a pot of good coffee. The casserole also pairs well with roasted tomatoes or a side of sautéed mushrooms for guests who want more vegetables on the plate. If you are building a larger brunch menu, this dish works beautifully next to a tater tot casserole for guests who want a starchier side.

For holiday occasions specifically, slice the casserole into smaller 2-inch squares and serve as part of a buffet table. Guests can take one or two pieces alongside other dishes, which means a single 9×13 pan can stretch to feed 16 to 18 people in a buffet format.

Storage and Reheating Instructions

Method	Duration	Instructions	Ready Indicator
Refrigerator storage	Up to 4 days	Cool completely, cover the dish tightly with plastic wrap or transfer to an airtight container	No sour or off smell; egg texture still firm and intact
Freezer storage	Up to 2 months	Slice into individual portions, wrap each in plastic wrap, place in a zip-top freezer bag	No ice crystals inside the egg; slices should look the same as when frozen
Microwave reheating	60 to 90 seconds	Place one square on a microwave-safe plate, cover loosely, heat on medium power	Warm through to the center; cheese melted and steaming slightly
Oven reheating	12 to 15 minutes at 325°F	Place portions in a baking dish, cover with foil, reheat from refrigerator temperature	Internal temperature reaches 165°F; edges are warm and cheese is re-melted
Overnight make-ahead (unbaked)	Up to 12 hours in fridge	Assemble the full casserole, cover tightly with plastic wrap, refrigerate overnight	Bake the next morning at 350°F; add 5 to 10 minutes to the standard bake time

Nutritional Information

Approximate values per serving (1 of 12 squares).

Nutrient	Amount per Serving
Calories	385 kcal
Carbohydrates	2g
Protein	23g
Total Fat	30g
Saturated Fat	12g
Cholesterol	239mg
Sodium	669mg
Potassium	327mg
Sugar	1g
Vitamin A	705 IU
Vitamin C	11.6mg
Calcium	194mg
Iron	1.8mg

Easy Breakfast Casserole Recipe

This breakfast casserole brings together beef sausage, a golden egg custard, colorful bell peppers, and sharp cheddar into one reliable, crowd-ready bake that works for any occasion.

Whether you build it the night before as a make-ahead breakfast casserole for Christmas morning or throw it together on a Saturday with whatever is in the fridge, every square delivers the same bold, savory flavor and satisfying texture. Make it once and it will become your go-to breakfast for a crowd.

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FAQs About Breakfast Casserole