A keto breakfast casserole is a delicious, satisfying way to start the day. Ready in about 35 minutes, this savory bake combines sausage, eggs, and cheese for a low-carb meal you can make any morning or prepare ahead for busy days, brunches, or holiday breakfasts.

This make-ahead breakfast casserole is simple to assemble and stores well. Bake it the night before and refrigerate the leftovers in an airtight container. Reheat portions in the oven or enjoy slices cold for an easy grab-and-go meal. The recipe is naturally low in carbohydrates and high in protein and fat, making it ideal for keto or low-carb meal plans.
Jump To:
- Why You’ll Love This Recipe
- How to Make Keto Breakfast Casserole
- Ingredients
- Step-by-Step Instructions
- Variations and Substitutions
- Expert Tips
- How to Store This Recipe
- How to Serve Egg and Sausage Casserole
- More Keto Casserole Ideas
Why You’ll Love This Recipe
Consistent, reliable recipes help build healthy habits and simplify meal planning. This low-carb breakfast casserole requires common ingredients, basic kitchen tools, and only a short prep and cook time. It’s flavorful, family-friendly, and portable — perfect for weekday breakfasts, meal prep, and casual brunches alike.
- Simple ingredients: Uses everyday items you may already have in your kitchen.
- Quick to make: About 15 minutes prep and 20 minutes baking.
- Big flavor: Savory sausage, creamy eggs, and melty cheese create a satisfying texture and taste while keeping carbs low.
- Kid-friendly: Mild flavors that appeal to most palates.
- Minimal equipment: Mixing bowl, whisk, skillet, and an 8×8-inch baking dish or similar casserole dish.

How to Make Keto Breakfast Casserole
Brown the sausage, whisk the eggs with cheese and seasonings, combine, and bake until set and golden. The method is straightforward and forgiving, so it’s great for cooks of any level.
Ingredients

These ingredients make a simple, satisfying casserole. Quantities in the recipe card below are for about 6 servings.
- 1 tablespoon butter
- 1 medium onion, diced
- 2 cloves garlic, minced
- 1 pound chicken sausage (or sausage of your choice), removed from casing and crumbled
- 10 large eggs
- 1 cup shredded cheddar cheese
- 1/4 cup shredded Parmesan
- 1/2 teaspoon dried thyme
- 1/2 teaspoon salt
- 1/2 teaspoon ground black pepper
Step-by-Step Instructions
Follow these simple steps to make the casserole. Exact times will vary slightly by oven and pan size.






Step 1: Sauté the aromatics
Preheat the oven to 350°F (175°C). Melt the butter in a skillet over medium heat and sauté the diced onion and minced garlic for about 5 minutes, until soft and translucent.
Step 2: Cook the sausage
Add the sausage to the pan, breaking it into small pieces with a spatula. Cook for about 8 minutes until browned and cooked through. Drain any excess fat if necessary.
Step 3: Whisk the egg mixture
In a large bowl, whisk the eggs until combined. Stir in the shredded cheddar, Parmesan, dried thyme, salt, and pepper. Mix gently until no visible streaks of yolk or white remain.
Step 4: Combine ingredients
Transfer the cooked sausage to an 8×8-inch baking dish and spread it evenly in a single layer. Pour the egg and cheese mixture over the top, then gently tap or jiggle the dish so the egg settles around the meat and fills the gaps.
Step 5: Bake and serve
Bake for about 20 minutes, or until the eggs are set in the center and the top is lightly golden. Allow the casserole to rest for 5 minutes before slicing. Serve warm.
Variations and Substitutions
This casserole is highly adaptable. Use the base method and swap or add ingredients to suit your taste or dietary preferences.
- Cheese: Any shreddable cheese works — Colby, Monterey Jack, mozzarella, Swiss, or Gruyère.
- Vegetables: Sautéed mushrooms, spinach, zucchini, or bell peppers are excellent low-carb additions.
- Proteins: Substitute ground beef, diced ham, pulled pork, or shredded turkey in place of sausage.
- Spice: Add hot sauce, crushed red pepper, or chili powder to give the casserole a kick.
- Carnivore option: Omit the onion, garlic, and herbs to keep the dish strictly meat, egg, and cheese.

Expert Tips
- Choose quality sausage: Look for minimally processed sausage without added sugars or fillers to keep this recipe keto-friendly and flavorful.
- Don’t overmix eggs: Whisk until combined but avoid beating excessively to prevent a tough texture.
- Test for doneness: A clean knife or toothpick inserted into the center should come out clean when the casserole is done.
How to Store This Recipe
Allow the casserole to cool completely before storing. Keep refrigerated in an airtight container for 4–5 days. For longer storage, portion and freeze for up to 3 months. Thaw overnight in the fridge and reheat in the oven until hot. Avoid repeated reheating to preserve texture and flavor.
How to Serve Egg and Sausage Casserole
This casserole is great on its own or paired with a light side like a cucumber salad or fresh greens. For larger gatherings, double the recipe and bake in a 9×13-inch dish. It pairs well with coffee or a warm, creamy tea for a satisfying brunch.
Nutrition and Recipe Notes
Approximate nutrition per serving (6 servings): 272 kcal, 6 g carbohydrates, 18 g protein, 20 g fat, net carbs about 5 g. For precise nutrition, calculate using the exact products and amounts you use.
If you try this casserole, adjust ingredients and seasoning to match your preferences — it’s one of the most flexible low-carb breakfasts you can make.