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–+ servings
Golden baked make ahead breakfast casserole cut into squares, loaded with melted cheese, fresh spinach, and diced red peppers, perfect for a quick and hearty morning meal.

Overnight Make-Ahead Egg and Sausage Casserole

A hearty, customizable breakfast casserole that can be prepped ahead for effortless mornings or festive gatherings.
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Prep Time 20 minutes
Cook Time 45 minutes
Hands-on time 20 minutes
Total Time 1 hour 25 minutes
Servings: 10
Course: Breakfast, Brunch
Cuisine: American, Comfort Food
Calories: 197
Ingredients Equipment Method Nutrition Notes

Ingredients
  

  • 10 to 12 ounces sausage removed casing, pre-cooked or raw
  • 2 teaspoons olive oil for sautéing vegetables
  • 2 cloves garlic minced for flavor
  • 3 cups fresh spinach washed and chopped
  • 2 large bell peppers diced, any color
  • ½ medium yellow onion diced for sweetness
  • Salt and pepper to taste
  • 12 large eggs room temperature for even cooking
  • ½ cup milk any variety, whole or low-fat
  • ½ cup shredded cheese any flavor, divided

Equipment

  • 1 Casserole dish 7x11 or 9x13 inch, non-stick or sprayed with oil
  • 1 Large skillet For browning meat and sautéing vegetables
  • 1 medium bowl For whisking eggs and milk
  • 1 Whisk For combining eggs and milk
  • 1 Non-stick spray For greasing the casserole dish
  • 1 Spatula For transferring cooked sausage and vegetables

Method
 

  1. Spray the casserole dish lightly with cooking spray and set aside. If baking immediately, preheat the oven to 375ºF (191ºC).
  2. In a large skillet over medium heat, cook the sausage until lightly browned. If using pre-cooked sausage, optionally brown for flavor. Transfer sausage to the prepared casserole dish.
  3. Add olive oil to the skillet if needed, then sauté garlic, spinach, bell peppers, and onion until tender and spinach is wilted, about 6-7 minutes. Season with salt and pepper at the end.
  4. Combine the cooked vegetables with the sausage in the casserole dish, stirring gently to mix evenly.
  5. Whisk together the eggs, milk, and ¼ cup of the shredded cheese in a medium bowl. Pour the mixture evenly over the sausage and vegetables, then sprinkle remaining ¼ cup cheese on top and season lightly.
  6. Bake the casserole in the preheated oven for approximately 45 minutes until the edges are golden brown. Allow to cool for at least 15 minutes before slicing.
  7. Store leftovers in the refrigerator up to 5 days. Reheat individual portions in the microwave as needed. For freezing, cover tightly with plastic wrap and foil; thaw overnight and bake at 350ºF (177ºC) for about 20 minutes.

Nutrition

Serving: 150gCalories: 197kcalCarbohydrates: 4gProtein: 13gFat: 14gSaturated Fat: 5gPolyunsaturated Fat: 2gMonounsaturated Fat: 6gTrans Fat: 0.1gCholesterol: 223mgSodium: 303mgPotassium: 277mgFiber: 1gSugar: 2gVitamin A: 1953IUVitamin C: 34mgCalcium: 88mgIron: 2mg

Notes

This casserole is perfect for busy mornings or holiday brunches—rich, flavorful, and packed with protein. It’s versatile enough to adapt to your favorite veggies or meats, making every bite a cozy start to the day.

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