Go Back
+ servings

Sausage and Mushroom Breakfast Casserole

A combination of browned sausage and mushrooms, bread, eggs, cheese and homemade mushroom gravy make up this delicious sausage and mushroom breakfast casserole.


  • ½ lb ground sausage
  • 8 ounces button or cremini mushrooms , sliced
  • 1 cup chopped onions (½ medium onion)
  • 6 tablespoons Challenge Salted Butter , divided
  • 2 tablespoons all-purpose flour
  • 2 cups milk , divided (whole or 2%)
  • About 1 teaspoon salt , to taste
  • About ½ teaspoon ground black pepper , to taste
  • 12 large eggs
  • 1 ½ cups shredded cheddar cheese
  • 6 cups cubed French, artisan or other white bread (about 8 slices)
  • Chopped fresh chives , for garnish (optional)


  • In a large skillet set over medium high heat, cook sausage until browned and cooked all the way through. Remove from skillet and set aside.
  • Add mushrooms and onions to the skillet and season with salt and pepper. Cook, stirring occasionally until softened, about 5 minutes. Remove from skillet and set aside with sausage.
  • Melt 2 tablespoons of butter to the skillet and add flour. Whisk to form a thick paste and cook for about 1 minute. Add 1 cup of milk gradually to the pan while whisking constantly. Bring to a simmer, stirring until sauce is smooth and thickened. Season with salt and pepper to taste. Set aside.
  • Melt the remaining ¼ cup butter in a dish. Whisk the butter with the remaining 1 cup of milk and the eggs. Add ½ teaspoon of salt and ¼ teaspoon pepper.
  • To assemble breakfast casserole, grease a 9x13 inch pan with butter. Spread bread cubes into an even layer in the pan. Carefully pour egg mixture over the bread cubes, making sure all the bread is moistened. Scatter sausage, mushrooms and onions evenly in the pan. Top with half of the cheese.
  • Spoon sauce over the casserole in heavy drizzles so there will be pockets of sauce among the other ingredients. Top with the rest of the cheese. Use the back of a spoon to gently push everything down into an even layer, and to make sure there are no dry pieces of bread.
  • Cover with foil and chill in the fridge overnight, or at least 4 hours.
  • When ready to bake, preheat oven to 350°F. Bake casserole covered for 45-60 minutes until casserole is puffed and set, taking off foil for the last 10-15 minutes.
  • Top with chives if desired. Serve immediately.


  • You can bake this casserole immediately after assembly, but chilling for at least 4 hours is recommended.
  • This casserole can be chilled in the fridge for up to 24 hours before baking.
  • If desired, you can use a can of cream of mushroom soup in place of the homemade gravy in this recipe. Warm it up so it has a spreadable consistency before spooning over casserole.


Sodium: 644mg, Calcium: 239mg, Vitamin C: 2mg, Vitamin A: 635IU, Sugar: 4g, Fiber: 1g, Potassium: 285mg, Cholesterol: 211mg, Calories: 326kcal, Trans Fat: 1g, Monounsaturated Fat: 7g, Polyunsaturated Fat: 2g, Saturated Fat: 11g, Fat: 22g, Protein: 16g, Carbohydrates: 16g, Iron: 2mg
Have you tried this recipe?I’d love to hear about it! Leave a review below or take a photo and tag it on Instagram @completelydelicious with #completelydelicious.