Classic Breakfast Casserole combines savory breakfast sausage, shredded potatoes, eggs, vegetables, and melted cheddar in one satisfying dish. It is filling enough for a weekend breakfast and easy to portion for holiday brunches or family gatherings.
The casserole can be assembled the night before and baked the following morning. Using thawed hash browns keeps the preparation simple while creating a hearty base that holds the sausage and egg mixture together.
Why You’ll Love This Recipe
- Combines eggs, sausage, potatoes, and cheese in one dish.
- Can be assembled ahead and refrigerated overnight.
- Feeds approximately eight people.
- Uses convenient frozen shredded hash browns.
- Can be customized with different meats and vegetables.
- Leftovers reheat well for quick breakfasts.
Ingredients
- Nonstick cooking spray, for the baking dish
- 1 pound breakfast sausage
- 1 small yellow onion, diced
- 1 medium red bell pepper, diced
- 20 ounces frozen shredded hash browns, thawed
- 2 cups shredded sharp cheddar cheese, divided
- 12 large eggs
- 1 cup whole milk
- 3/4 teaspoon kosher salt
- 1/2 teaspoon ground black pepper
- 1/2 teaspoon garlic powder
- 2 green onions, thinly sliced, for serving
Thawed hash browns create the potato layer without requiring peeling or grating. Breakfast sausage adds seasoning and richness, while sharp cheddar provides enough flavor without needing a large amount of cheese.
Ingredient Substitutions
- Breakfast sausage: Use cooked bacon, diced ham, turkey sausage, or plant-based breakfast sausage.
- Frozen hash browns: Substitute approximately 3 cups of refrigerated shredded potatoes.
- Sharp cheddar: Use Monterey Jack, Colby, pepper Jack, or a Mexican-style cheese blend.
- Whole milk: Use 2% milk, half-and-half, or unsweetened plain nondairy milk.
- Red bell pepper: Substitute green bell pepper, poblano pepper, or chopped mushrooms.
- Yellow onion: Use a white onion, red onion, or 1 teaspoon onion powder.
- Green onions: Fresh parsley or chives can be used for garnish.
How to Make Breakfast Casserole
- Prepare the baking dish.
Preheat the oven to 375°F. Coat a 9-by-13-inch baking dish with nonstick cooking spray. - Cook the sausage.
Place the breakfast sausage in a large skillet over medium-high heat. Cook for 5 to 7 minutes, breaking it into small pieces, until browned and no pink remains. - Add the vegetables.
Add the diced onion and bell pepper to the skillet. Cook for another 4 to 5 minutes, stirring occasionally, until the vegetables soften. - Drain excess grease.
Remove the skillet from the heat. Carefully drain any significant amount of rendered fat so the casserole does not become greasy. - Prepare the hash browns.
Pat the thawed hash browns with paper towels or a clean kitchen towel to remove excess moisture. Spread them evenly over the bottom of the prepared baking dish. - Add the sausage and cheese.
Distribute the sausage and vegetable mixture over the potatoes. Sprinkle 1 1/2 cups of cheddar evenly over the sausage. - Prepare the egg mixture.
In a large bowl, whisk the eggs until the yolks and whites are completely combined. Add the milk, salt, black pepper, and garlic powder. Whisk again until smooth. - Assemble the casserole.
Slowly pour the egg mixture over the sausage, potatoes, and cheese. Gently press any exposed ingredients into the liquid without compacting the layers. - Add the remaining cheese.
Sprinkle the remaining 1/2 cup cheddar over the top. - Bake.
Bake uncovered for 40 to 45 minutes. The edges should be lightly golden, and the center should look set without any visible liquid. An instant-read thermometer inserted into the center should register 160°F. - Rest before serving.
Let the casserole rest for 10 minutes. Sprinkle with sliced green onions, then cut it into squares and serve.
Tips for the Best Classic Breakfast Casserole
- Thaw the hash browns completely before assembling the casserole.
- Remove excess moisture from the potatoes to prevent a watery result.
- Drain the cooked sausage before adding it to the baking dish.
- Whisk the eggs thoroughly for an even texture.
- Spread the ingredients evenly so every serving contains sausage, potatoes, and cheese.
- Check the center rather than relying only on the browned edges.
- Rest the casserole before slicing so the portions hold together.
Common Mistakes to Avoid
Using Frozen Hash Browns Without Thawing
Frozen potatoes release water as they cook and may prevent the center from setting evenly. Thaw and dry them first.
Leaving Excess Grease in the Sausage
Too much rendered fat can pool around the edges. Drain the sausage mixture before assembling the casserole.
Overbaking the Eggs
Eggs become rubbery when cooked too long. Remove the casserole once the center is set and reaches 160°F.
Cutting the Casserole Immediately
Freshly baked egg casserole is delicate. Let it rest for 10 minutes so the layers can firm up.
Using a Baking Dish That Is Too Small
A smaller dish creates a thick casserole that takes longer to cook. Use a standard 9-by-13-inch dish for even baking.
Variations
Bacon Breakfast Casserole
Replace the sausage with 12 slices of cooked, crumbled bacon. Sauté the onion and bell pepper separately before assembling.
Ham and Cheese Breakfast Casserole
Replace the sausage with 2 cups of diced cooked ham. Swiss cheese can replace some or all of the cheddar.
Vegetable Breakfast Casserole
Omit the sausage and use 3 cups of cooked vegetables, such as mushrooms, spinach, bell peppers, or broccoli. Remove excess moisture before adding them.
Spicy Breakfast Casserole
Use hot breakfast sausage and pepper Jack cheese. Add one finely diced jalapeño with the bell pepper.
Extra-Cheesy Breakfast Casserole
Increase the cheese to 3 cups and use a combination of cheddar, Monterey Jack, and mozzarella.
What to Serve With Classic Breakfast Casserole
- Fresh fruit salad
- Toast, biscuits, or English muffins
- Pancakes or waffles
- Greek yogurt with berries
- Simple green salad
- Coffee, tea, milk, or orange juice
How to Store
Allow the casserole to cool before covering the baking dish or transferring individual portions to an airtight container. Refrigerate for up to 4 days.
To freeze, wrap individual portions tightly and place them in a freezer-safe container. Freeze for up to 2 months and thaw overnight in the refrigerator.
Reheat individual portions in the microwave in short intervals. For several servings, cover the baking dish with foil and warm it in a 325°F oven until heated through. Avoid prolonged reheating, which can dry out the eggs.
Frequently Asked Questions
Can I assemble the casserole the night before?
Yes. Assemble it completely, cover it tightly, and refrigerate overnight. Let the dish stand at room temperature while the oven preheats, then bake as directed. It may require 5 to 10 additional minutes.
Do I need to cook the sausage first?
Yes. Cooking the sausage removes excess fat and ensures it is evenly distributed throughout the casserole.
Can I use fresh potatoes?
Yes. Peel and shred approximately 3 medium russet potatoes. Squeeze them thoroughly in a clean kitchen towel to remove as much moisture as possible.
Why is my breakfast casserole watery?
The hash browns or vegetables may have contained excess moisture, or the casserole may not have baked long enough. Dry the ingredients well and check the center before removing it from the oven.
Can I make this casserole without milk?
Yes. Replace the milk with unsweetened plain nondairy milk or use an additional two eggs. The version without milk will have a firmer texture.
Should breakfast casserole be covered while baking?
It does not need to be covered. If the cheese begins browning before the center is set, loosely cover the dish with foil for the remaining baking time.
How do I know when the casserole is done?
The center should be set and should not jiggle like liquid when the dish is moved. An instant-read thermometer should register 160°F in the middle.
Final Thoughts
Classic Breakfast Casserole makes it easy to serve a complete breakfast from one baking dish. Thaw and dry the potatoes, drain the sausage, and let the casserole rest after baking for neat portions with a tender center.
[…] Classic Breakfast Casserole […]