This easy breakfast casserole is made with eggs, sausage, and cheese and comes together quickly and easily. Makes the best make-ahead breakfast casserole!
Prep the casserole dish. Spray 9x13 casserole dish with nonstick cooking spray or coat it with butter and set aside.
Cook the sausage and vegetables. Crumble sausage in a medium skillet with onion and garlic (and other vegetables if using). Cook over medium heat until the sausage is browned and cooked throughout and the onion is tender. Drain and set aside.
Add the cubed bread. Arrange the cubed biscuits in the bottom of the prepared casserole dish.
Mix the casserole filling. Whisk the milk, eggs, salt, pepper, and dry mustard in a mixing bowl. Stir in the shredded cheese, sausage, and cooked vegetables. Pour over the cubed biscuits.
Bake and serve. Refrigerate for 30 minutes to overnight. When ready to bake, preheat the oven to 350º F. Bake for 40 to 45 minutes, until the center of the casserole is just set and registers 160º F in the center when checked with an instant read thermometer. Allow to stand for about 10 minutes before serving.
Video
Notes
Ingredient Substitutions:Stone House Seasoning - Substitute 1 teaspoon for the garlic, salt, and pepper listed in the recipe. Recipe Variations:Vegetarian Breakfast Casserole - Omit the meat and add about 1 cup more vegetables. Proceed with the recipe as written.Potato Breakfast Casserole - Omit the bread and use 3 cups frozen diced hashbrowns (found in the grocery store's freezer section) or diced fresh potatoes cooked until browned about 10 minutes. Proceed with the recipe as written.Half Recipe - Half the ingredients and prepare in a 9x9 baking dish. Bake for 30 to 35 minutes.Storage Tips:Leftovers. Cover with plastic wrap and store in the refrigerator for three to four days. Reheat in the microwave or in a 350º F oven.Make Ahead. You can prepare this breakfast casserole up to 24 hours in advance and keep it tightly wrapped in the refrigerator. Then, on the morning you are serving, just bake for about 40-45 minutes until the casserole is set. Remove it from the oven and allow it to stand at room temperature for a few minutes before serving.Freezer Instructions. Prepare the unbaked breakfast casserole through step 4 of the recipe in a freezer-safe baking dish. Wrap tightly with plastic wrap topped by foil. Freeze for up to 3 months. Thaw in the refrigerator overnight then bake as directed. To freeze the baked breakfast casserole, prepare the casserole in a freezer-safe baking dish. Cool completely after baking. Wrap tightly with plastic wrap, topped by aluminum foil. Freeze for up to 3 months. Thaw in the refrigerator overnight. Remove the plastic wrap and return the foil cover to the baking dish. Bake at 350º F until reheated throughout, about 30 minutes.