Overnight Sausage, Egg, and Potato Breakfast Casserole (Holiday Brunch)

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This Sausage, Egg, and Potato Breakfast Casserole is the perfect way to start any celebration morning. It combines savory breakfast sausage, tender hashbrown potatoes, colorful bell peppers, and gooey cheese, all baked into a rich egg custard. Best of all, this delicious dish is designed to be a complete overnight potato breakfast casserole—you assemble it the night before and enjoy a stress-free morning!

What sets this sausage egg cheese bake with potatoes apart is the depth of flavor from sautéing the vegetables with the sausage. This ensures every layer is seasoned, not just the top. By using hashbrowns, you get a hearty, satisfying base that soaks up the egg mixture beautifully, promising a moist and flavorful result that easily feeds a large crowd.

Why You’ll Love This Casserole

• Overnight Prep: Assemble and refrigerate for a minimum of 8 hours, minimizing work on the day of the event.
• Hearty Base: The potato layer provides a satisfying, “stick-to-your-ribs” base for the eggs and meat.
• Complex Flavor: Includes bell peppers (red and green), onion, and garlic for a classic savory, aromatic profile.
• Feeds a Crowd: The perfect easy holiday brunch casserole for Christmas, Easter, or a large family gathering.

Ingredients

• 1 lb Ground Breakfast Sausage (or ground turkey sausage)
• 1 Green Bell Pepper, diced
• 1 Small Onion, diced
• 1 Red Bell Pepper, diced
• 2 tsp Minced Garlic
• 3 cups Cubed Hash Brown Potatoes (thawed or fresh cubed potatoes)
• 6 large Eggs
• ⅓ cup Milk (whole milk or half-and-half)
• 2 cups Cheddar Cheese, shredded (divided)
• Salt and Pepper, to taste
• ½ tsp Red Pepper Flakes (optional, for spice)
• Green Onions, chopped (for garnish)

Instructions (Step-by-Step)

1. Prep Meat and Veggies: Preheat oven to 400°F (200°C). Cook the sausage over medium-high heat until no longer pink. Drain off all excess grease. Add the green peppers, red peppers, onion, and garlic to the pan and cook for an additional 5 minutes until softened.
2. Layer the Base: In a greased 9×13-inch baking dish, spread half of the hashbrown potatoes. Sprinkle half of the cooked sausage mixture evenly over the potatoes. Sprinkle 1 cup of the shredded cheddar cheese over the sausage.
3. Layer Top Half: Layer the remaining hashbrowns, the remaining sausage mixture, and the remaining cheese over the top of the first layers.
4. Prepare Custard: In a medium bowl, whisk together the eggs, milk, salt, pepper, and optional red pepper flakes until fully combined. Pour the egg mixture evenly over the layers in the baking dish.
5. Assemble Overnight: Cover the dish tightly and refrigerate for a minimum of 8 hours (or overnight).
6. Bake: In the morning, remove the plastic wrap. Bake at 350°F for 35–40 minutes, or until the eggs are fully set and a knife inserted near the center comes out clean.
7. Serve: Sprinkle with green onions and serve.

Storage and Reheating

• Overnight Prep is Key: The refrigeration step is essential for the potatoes to soften and the flavors to meld.
• Storage: Store leftovers in an airtight container in the refrigerator for up to 3 days.
• Freezing: This casserole can be baked, cooled, and frozen in portions for up to 1 month.

Expert Tips

• Potatoes Must Be Prepared: If using frozen shredded hash browns, ensure they are thawed before mixing. If using fresh potatoes, cube them small and par-cook them slightly (blanching or microwaving for a few minutes) to ensure they cook completely in the oven.
• No Soggy Veggies: Sautéing the bell peppers and onions with the sausage not only adds deep flavor but also removes excess moisture, preventing the final casserole from turning watery.
• Don’t Forget the Seasoning: The sausage egg potato breakfast casserole needs seasoning in the egg mixture to prevent blandness. Don’t rely solely on the salt from the sausage.
• High Heat Start: Starting the vegetables at a medium-high heat ensures they are cooked quickly and retain a nice texture, rather than steaming.

Variations

• Spicy Southwester: Use hot sausage and add 1 can of diced green chilies (drained) to the vegetable mixture.
• Bread Base: Substitute the hashbrowns with 6 slices of cubed bread (soaked overnight in the egg mixture) for a lighter texture.
• Meat Swap: Use pre-cooked ham, bacon, or ground turkey sausage.

Serving Suggestions

Serve this savory casserole with classic complements:

• Sweet Contrast: Fresh fruit salad, juice, or a cinnamon roll on the side.
• Sauces: Ketchup, salsa, or sour cream.

Frequently Asked Questions

Q: Can I put the frozen hash browns directly into the casserole without thawing? A: No, it is highly recommended to thaw the hash browns first. Frozen potatoes will release too much water during the bake time, which will make the egg custard watery and prevent the center from setting properly.

Q: How do I know when the sausage egg potato casserole is fully cooked? A: The casserole is done when the edges are set and a knife inserted near the center comes out clean. If the center jiggles significantly, it needs more time. The internal temperature should be 160°F–165°F.

Q: Can I mix all the ingredients, including the eggs, and freeze the casserole uncooked? A: It is not recommended to freeze the uncooked casserole. Freezing raw eggs and milk can cause the dairy to separate and the texture of the eggs to become rubbery when thawed and baked. Freeze the cooked meat/veg mixture separately and add the fresh egg custard right before baking.

Q: Can I add a different cheese, like Swiss or Gruyere? A: Yes. Any good melting cheese works well. Gruyere, Pepper Jack, or a blend of Monterey Jack and Cheddar provides a great flavor contrast to the sausage.