Overnight Sausage and Caramelized Onion Breakfast Casserole is a great breakfast for the holidays. Full of cubed challah bread, sausage, caramelized onions, and two types of cheese.
Overnight Breakfast Casseroles are perfect for the holidays and I love assembling one on Christmas Eve and popping it in the oven Christmas morning. After 40 minutes in the oven, this casserole gets crispy and golden around the edges. It’s so savory and delicious.
The caramelized onions are what make this an amazingly tasty breakfast casserole. They add a wonderful sweetness and pair perfectly with the sausage.
How To Make This Sausage and Caramelized Onion Breakfast Casserole Spicy?
Use “Hot” breakfast sausage and add 1/2 teaspoon of crushed red pepper flakes.
Leftovers will keep in an airtight container in the refrigerator for 4 to 5 days. Can be reheated in the microwave, air fryer, or toaster oven.
Not only for the holidays, this casserole works anytime of year.
French or Italian Bread can be used instead of challah bread.
When you take it out of the oven, check to make sure the center is set and not runny. If the top starts to get too browned before it is done, cover it with foil.
I’m a huge fan of breakfast casseroles. They’re so easy for feeding a house full of people.
Try These Other Amazing Breakfast Casseroles:
- Sausage and Crescent Roll Casserole
- Breakfast Tater Tot Casserole
- Sausage and Cheese English Muffin Casserole
- Eggs Benedict Casserole
- 1 pound breakfast sausage
- 1 tablespoon vegetable oil
- 1 tablespoon butter
- 1 medium yellow or sweet onion, thinly sliced
- 1/2 red bell pepper, diced
- 6 cups day old challah bread cubes
- 6 large eggs
- 1 1/4 cups half-and-half
- 3/4 teaspoon salt
- 1/2 teaspoon dry mustard
- 1/2 teaspoon dried thyme
- 1/8 teaspoon ground nutmeg
- 1 cup shredded cheddar cheese
- 1 cup shredded mozzarella cheese
- Cook and crumble the sausage in a large nonstick skillet. Remove to a bowl with a slotted spoon.
- Add oil and butter to the grease in the skillet and cook onion over medium heat for 8 minutes.
- Add red bell pepper and cook another 5 minutes. Season mixture with salt and pepper.Add to bowl with sausage.
- Place bread cubes in the bottom of a greased 7x11-inch baking dish. Preheat oven to 350 degrees.
- Scatter sausage mixture on top of bread cubes.
- In a medium bowl, whisk together eggs, half-and-half, salt, dry mustard, thyme, and nutmeg.
- Sprinkle half the cheddar and mozzarella over sausage mixture.
- Pour egg mixture evenly over casserole.
- Sprinkle remaining cheese on top. Bake uncovered in a 350 degrees for 40 minutes.
Want to Save This Recipe?
Disclosure: This post contains affiliate links.