Spicy Sausage Mushroom and Swiss Breakfast Casserole

Start your morning with the bold flavors of this Spicy Sausage Mushroom and Swiss Breakfast Casserole—a savory, make-ahead breakfast that’s perfect for feeding a crowd. Packed with spicy breakfast sausage, tender sautéed mushrooms, sweet caramelized onions, and creamy Swiss cheese, this casserole combines layers of flavor and texture in every bite. The egg-soaked cubes of day-old bread create a fluffy, custardy base, while a touch of cayenne pepper brings just the right amount of heat. Topped with golden, melty cheese and optional green onion garnish, this hearty dish is easy to prepare and bakes to perfection in under an hour. Ideal for holiday gatherings, lazy weekend brunches, or meal prep, this casserole proves that breakfast can be both satisfying and gourmet.

Nutriscore Rating: 64/100

Prep Time:20 mins

Cook Time:50 mins

Total Time:70 mins

Servings: 8

Ingredients

• 1 pound spicy breakfast sausage
• 2 tablespoons butter
• 8 ounces mushrooms, sliced
• 1 medium yellow onion, diced
• 2 cloves fresh garlic, minced
• 10 large eggs
• 1.5 cups whole milk
• 0.5 teaspoons ground black pepper
• 0.5 teaspoons salt
• 0.25 teaspoons ground cayenne pepper (optional)
• 6 cups day-old bread, cubed
• 2 cups shredded Swiss cheese
• 2 stalks green onions, sliced (optional for garnish)

Directions

Step 1

Preheat your oven to 375°F (190°C) and grease a 9x13-inch baking dish with cooking spray or butter.

Step 2

In a large skillet over medium heat, cook the spicy breakfast sausage, breaking it into small crumbles with a spatula. Cook until browned and fully cooked through, about 6-8 minutes. Remove the sausage with a slotted spoon and set aside, leaving the grease in the pan.

Step 3

Add the butter to the skillet with the sausage grease. Once melted, add the sliced mushrooms, diced onion, and a pinch of salt. Sauté for 6-7 minutes, or until the mushrooms are tender and the onions are translucent. Stir in the minced garlic and cook for an additional 1 minute. Remove from heat and set aside.

Step 4

In a large mixing bowl, whisk together the eggs, whole milk, ground black pepper, salt, and cayenne pepper (if using), until thoroughly combined.

Step 5

Add the cubed bread to the egg mixture, tossing carefully to coat the bread evenly. Let sit for 5 minutes to allow the bread to absorb the liquid.

Step 6

Stir in the cooked sausage, sautéed mushrooms and onions, and 1.5 cups of the shredded Swiss cheese. Mix until evenly distributed.

Step 7

Pour the mixture into the prepared baking dish. Spread it out evenly and sprinkle the remaining 0.5 cup of shredded Swiss cheese on top.

Step 8

Cover the casserole tightly with aluminum foil and bake in the preheated oven for 30 minutes.

Step 9

Remove the foil and bake for an additional 15-20 minutes, or until the top is golden brown and the center is set (a knife inserted into the center should come out clean).

Step 10

Remove the casserole from the oven and let it rest for 5-10 minutes before slicing.

Step 11

Garnish with sliced green onions (if desired) and serve warm. Enjoy!

Nutrition Facts

Serving size	(3389.1g)

Amount per serving	% Daily Value*
Calories	7498.9

Total Fat 338.4g	0%
Saturated Fat 132.6g	0%
Polyunsaturated Fat 1.1g
Cholesterol 2488.2mg	0%
Sodium 13619.2mg	0%
Total Carbohydrate 779.4g	0%
Dietary Fiber 54.4g	0%
Total Sugars 77.7g
Protein 348.2g	0%

Vitamin D 646.2IU	0%
Calcium 3833.4mg	0%
Iron 63.7mg	0%
Potassium 4947.9mg	0%

*The % Daily Value tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.

Source of Calories

Fat: 40.3%

Protein: 18.4%

Carbs: 41.3%