Easy high-protein breakfast casserole is the perfect make-ahead meal for busy mornings.
Packed with eggs, lean turkey sausage, cheese, and vegetables, it’s hearty enough to keep you energized until lunch.
Bake it on the weekend and enjoy grab-and-go portions all week long. Great on its own or paired with fresh fruit, avocado slices, or whole-grain toast.

Easy High-Protein Breakfast Casserole for Busy Mornings
Ingredients
Equipment
Method
- Preheat Oven: Set your oven to 375°F (190°C). Grease a 9×13-inch baking dish with cooking spray or olive oil.Cook the Sausage: In a skillet over medium heat, cook the turkey sausage until browned, breaking it apart with a spatula. Drain excess fat if needed.
- Sauté Veggies: Add diced onion and bell peppers to the skillet. Cook for 4–5 minutes until softened. Stir in spinach and cook until just wilted. Remove from heat.Whisk Eggs: In a large mixing bowl, whisk together eggs, egg whites, milk, garlic powder, paprika, salt, and black pepper.
- Assemble Casserole: Spread the cooked sausage and veggies evenly in the baking dish. Pour the egg mixture over the top, then sprinkle with shredded cheddar cheese.Bake: Place in the preheated oven and bake for 35–40 minutes, or until the center is set and a knife inserted comes out clean.
- Cool & Serve: Let it cool for 5–10 minutes before slicing into 6 portions. Serve warm or refrigerate for up to 5 days.
Video
Notes
Nutrient | Amount per Serving (~220g) |
---|---|
Calories | 280 |
Carbohydrates | 6 g |
Protein | 29 g |
Fat | 14 g |
Saturated Fat | 5 g |
Polyunsaturated Fat | 2 g |
Monounsaturated Fat | 4 g |
Trans Fat | 0 g |
Cholesterol | 260 mg |
Sodium | 620 mg |
Potassium | 480 mg |
Fiber | 1 g |
Sugar | 3 g |
Vitamin A | 2100 IU (42% DV) |
Vitamin C | 35% DV |
Calcium | 180 mg (18% DV) |
Iron | 2.5 mg (14% DV) |
Cooking Tips
- Swap in Greek yogurt in place of some milk for extra creaminess and protein.
- Use different veggies like zucchini, mushrooms, or broccoli to switch things up.
- Make it spicy by adding jalapeños or a dash of hot sauce.
- For a meal-prep boost, cut into squares and wrap individually for quick reheating.
Serving Ideas for Your High-Protein Breakfast Casserole
This high-protein breakfast casserole is incredibly versatile and can be served in a variety of ways to suit different mornings or dietary needs.
For a quick weekday breakfast, simply reheat a slice in the microwave and enjoy it as-is, no extras needed.
If you’re craving something heartier, pair it with a slice of whole-grain toast or an English muffin to add a dose of complex carbs. A small side of fresh fruit like berries, orange slices, or a banana complements the savory flavor and adds natural sweetness without extra sugar.
For a more elevated brunch option, serve each slice with a dollop of Greek yogurt or avocado slices on top. You can also turn it into a wrap, just roll up a warm piece of the casserole in a whole-wheat tortilla with some salsa or hot sauce for a delicious on-the-go breakfast burrito.
If you’re feeding a crowd, consider offering a toppings bar with extras like chopped green onions, jalapeños, hot sauce, or even crumbled feta or goat cheese, so everyone can customize their own plate.

Alternative Ingredients for Customizing Your Breakfast Casserole
One of the best things about this high-protein breakfast casserole is how adaptable it is.
Whether you’re working with dietary restrictions, personal preferences, or simply using what you have on hand, there are plenty of easy ingredient swaps that keep the dish just as delicious and nutritious.
Swapping ingredients is also a great way to keep the recipe fresh week after week.
Here are some popular alternatives you can try:
Category | Main Alternative | Additional Option |
---|---|---|
Protein Options | Chicken sausage, lean ground beef, or plant-based sausage crumbles | Add diced cooked bacon or ham |
Vegetables | Zucchini, broccoli florets, mushrooms, or kale | Use thawed and drained frozen vegetables |
Cheese | Pepper jack, mozzarella, or Swiss | Use plant-based cheese for a dairy-free version |
Egg Alternatives | Replace whole eggs with additional egg whites | Use a liquid egg substitute like Egg Beaters |
Milk Options | Unsweetened soy, oat, or almond milk | Use 2% or whole milk for added richness |
These swaps make the casserole more flexible and inclusive for different diets, including vegetarian, dairy-free, and low-carb lifestyles, without compromising on taste or texture.
Summary
Make-ahead meals like high-protein breakfast casseroles are a simple way to stay fueled without sacrificing time or flavor.
With just a few ingredient swaps, it becomes easy to adjust for dietary needs, pantry limitations, or personal tastes.
Keep a batch in the fridge for busy mornings or serve it as part of a weekend brunch. It’s flexible, filling, and fits into just about any routine.
Try it once, and it might just become part of your weekly rotation.
Find out more and delicious no-cook, no-refrigeration dishes here!

Hi there, my name is Kelly Barlow and kellytoeat.com is my blog. Here, I write about various recipes I want to reccommend to readers.
I try to find the best possible recipes that can attract the attention of readers, and at the same time, I strive to write it in the most engaging manner possible.
When I was younger, I wanted to become a chef. Sadly, it wasn’t meant to be, but at the very least, I write about it.