This Make-Ahead, Overnight Breakfast Casserole is a delicious way to fuel up for the day. With hearty potatoes, crunchy red peppers, savory sausage, and melted cheese, this is a delectable breakfast that is perfect to feed a crowd!
Overnight Breakfast Casserole

Over the holidays and general busy seasons of our lives, make-ahead and overnight breakfast recipes can save the day.
This Overnight Breakfast Casserole is a make-ahead dish that easily feeds a crowd. I've made it when we've hosted Christmas brunch, and also just weekend brunch with friends. It's also an amazing dish to make just for your family. You can refrigerate half of leftovers for breakfasts all week long. And you can freeze the other half to enjoy at a later date!
Delicious Overnight Breakfast Casserole

This breakfast/brunch recipe has all of the classic breakfast staples:
- potatoes
- sausage
- cheese
- eggs
Plus, it's topped with a layer of ooey gooey cheese to make each bite extra flavorful!
Tips for making this hearty breakfast recipe
Most of the work for this delicious breakfast happens the night before.
You start by browning the sausage, then the veggies.
Then you combine the sausage and veggies, plus a portion of the cheese, with an egg, milk, pepper mix.
Spread this entire mixture evenly into an oven-safe baking dish, sprinkle the remaining cheese, cover, and refrigerate overnight.
When you are ready to bake, preheat the oven to 350°F. Take the pan out of the refrigerator and allow it to come to room temperature. Letting it sit on the kitchen counter for 20-30 minutes should do.
Bake, covered, for 30 minutes. Then remove the foil and bake for an additional 15-20 minutes. Remove and allow to rest at room temperature for about 5 minutes before serving.
Exact measurements of ingredients and instructions are in the printable recipe card toward the bottom of this post. Here are some helpful tips to guide you as you make this recipe.
How long do breakfast casseroles last?

Store this breakfast casserole in the refrigerator for up to five days. It's a fantastic dish to make on a Sunday, and then you have an easy breakfast for the rest of the week. Simply reheat in the microwave when you're ready to enjoy a portion.
You can also freeze this overnight breakfast casserole. Place it in an airtight, freezer-friendly container and store in your freezer for up to two months. When you're ready to serve it again, let it thaw in the refrigerator overnight. Then either reheat small portions in the microwave, or bake in an oven-safe pan at 350°F for about 15-20 minutes.
This is my favorite 9x13 freezer-to-oven dish. Perfect for baking, freezing, and then reheating without needing to switch dishes!
More make-ahead recipes
Overnight Orange Cinnamon Rolls with Cardamom
Chocolate Peanut Butter Overnight Oats
Cheese and Spinach Mini Frittata Recipe
Make Ahead Breakfast: Overnight Baked Brioche French Toast

Make-Ahead Breakfast Casserole
Ingredients
Instructions
- Heat olive oil in a large saute pan over medium-high heat. Add the sausage, break apart and crumble with a spoon, and cook until browned.Using a slotted spoon, remove sausage from the pan and transfer to a large mixing bowl. Set aside.
- Add onion, red pepper, and potatoes to the sauté pan, and sauté for 5 minutes, softening the onion and red pepper and lightly cooking the potatoes. Then add the garlic and sauté for an additional 2 minutes until softened. Add this vegetable mixture into the mixing bowl with the sausage. Add 1 ½ cups cheese to the mixing bowl with the sausage and veggies. Stir to combine.
- In a separate bowl, whisk together the eggs, milk, and black pepper. Then add this egg mixture to the bowl with the hashbrown mixture, and stir to combine. Carefully pour the combined ingredients into a 9×13-inch baking dish. Top with the remaining ½ cup of shredded cheese. Cover with aluminum foil and refrigerate overnight.
- In the morning, remove from the refrigerator and let sit for a few minutes at room temperature while you preheat the oven to 375°F.
- Cover with foil and bake for 30 minutes. Remove the aluminum foil and bake for an additional 15-20 minutes, until the potatoes are cooked through.
- Remove and let the casserole rest for 5 minutes. Garnish with parsley or green onions and serve immediately.
Notes
Nutrition
Nutrition information is a general estimate. Actual nutrition details may vary depending on the exact foods & brands you use to make this recipe. It does not take into account any substitutions, toppings, or optional ingredients.
PIN IT:

Marlena Durrett says
Can you make this and immediately bake or does he have to sit overnight?
Than you
Marlynn Jayme Schotland says
Yes, you can make it immediately too!