Overnight Breakfast Casserole
A layered, savory casserole featuring breakfast sausage, bacon, and cheese, perfect for make-ahead meals that feed a crowd.
Ingredients
Meats
- 1 pound bulk breakfast sausage Brown and crumble; it’s the primary savory flavor. (Sub: ground turkey for lighter texture.)
- 8 ounces bacon Cook, crumble, and split: half folded into the casserole, half sprinkled on top for crunch. (Sub: Canadian bacon or smoked ham.)
Vegetables
- 2 tablespoons green onions Sliced fresh garnish to brighten the dish.
Potatoes and Dairy
- 1 pound shredded potatoes Thawed hash browns; pat dry before layering to prevent a watery casserole. (Sub: frozen diced potatoes or freshly shredded russet potatoes squeezed dry.)
- 2 cups cheddar cheese Divided; sharp cheddar gives classic flavor.
- 6 large eggs The binder that sets the casserole into a custardy texture.
- 2 cups milk Whole milk gives best richness; 2% works for a lighter version.
Condiments and Seasonings
- 1 tablespoon Dijon mustard Adds subtle tang and depth; don’t skip.
- 1 teaspoon salt Seasoning backbone.
- 1 teaspoon coarse ground pepper Seasoning backbone.
Instructions
Preparation
- Preheat oven to 350°F (175°C). Grease a 9×13-inch baking dish.
- In a skillet over medium-high heat, cook 1 pound bulk breakfast sausage, breaking it into crumbles until browned and no longer pink (about 6–8 minutes). Drain excess fat.
- Cook 8 ounces bacon until crisp. Drain and pat dry; crumble. Set aside half for mixing and half for topping.
- If your shredded potatoes are very wet, squeeze excess moisture in a clean towel.
- Layer the bottom of the prepared dish with the thawed shredded potatoes in an even layer.
- Sprinkle half of the 2 cups shredded cheddar over the potatoes, then add the browned sausage and the crumbled bacon reserved for mixing.
Custard Mixture
- In a large bowl, whisk together 6 large eggs, 2 cups milk, 1 tablespoon Dijon mustard, 1 teaspoon salt, and 1 teaspoon coarse ground pepper until combined.
- Pour the egg mixture evenly over the layered ingredients. Press gently so the liquid settles into the layers.
- Cover the dish with plastic wrap and refrigerate overnight, or for at least 4 hours to let flavors meld and the custard absorb into the potatoes.
Baking
- When ready to bake, remove plastic wrap and top with the remaining cheddar and the reserved crumbled bacon for topping.
- Bake uncovered at 350°F (175°C) for 45–55 minutes, or until the center is set and the top is golden.
- Let rest 10 minutes before slicing. Garnish with 2 tablespoons sliced green onions just before serving.
Notes
Cover leftovers and refrigerate within two hours of baking. Store up to 3–4 days. Reheat individual slices in the microwave (about 60–90 seconds) or in a 350°F oven covered with foil until warm throughout (15–20 minutes). Use a food thermometer to confirm proper reheating temperatures.