Low Carb Breakfast Casserole – A Cozy, Easy Morning Favorite

This low carb breakfast casserole is the kind of recipe you keep coming back to. It’s warm, savory, and packed with protein to keep you full well past noon. You can prep it ahead, bake it fresh, or slice it for easy grab-and-go breakfasts through the week.

It’s also flexible, so you can use what you have on hand. If you love a satisfying breakfast that doesn’t weigh you down, this one’s a keeper.

Low Carb Breakfast Casserole - A Cozy, Easy Morning Favorite

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Prep Time 15 minutes mins

Cook Time 40 minutes mins

Total Time 55 minutes mins

Servings 8 servings

Ingredients

  

• 12 large eggs
• 1 cup heavy cream (or unsweetened almond milk for lighter)
• 1 pound breakfast sausage (pork or turkey, no sugar added)
• 1 cup shredded cheddar cheese (or a blend like cheddar–Monterey Jack)
• 1 cup bell peppers, diced (any color)
• 1 small yellow onion, diced
• 2 cups fresh spinach, roughly chopped
• 2 cloves garlic, minced
• 2 tablespoons olive oil or butter
• 1 teaspoon kosher salt (plus more to taste)
• 1/2 teaspoon black pepper
• 1/2 teaspoon smoked paprika (optional but great for depth)
• 1/2 teaspoon dried oregano or Italian seasoning
• Chopped fresh parsley or chives for garnish (optional)

Instructions

 

• Preheat the oven. Set it to 375°F (190°C). Grease a 9x13-inch baking dish with olive oil, butter, or cooking spray.
• Cook the sausage. In a large skillet over medium heat, brown the sausage, breaking it into small pieces. Cook until no longer pink and lightly crispy. Drain excess fat if needed and set aside.
• Sauté the veggies. In the same skillet, add olive oil or butter. Sauté onion and bell peppers with a pinch of salt for 4–5 minutes, until softened. Add garlic and cook 30 seconds. Stir in spinach just until wilted. Remove from heat.
• Whisk the eggs. In a large bowl, whisk eggs, heavy cream, salt, pepper, smoked paprika, and oregano until smooth and slightly frothy.
• Layer the dish. Spread the cooked sausage evenly in the baking dish. Scatter the sautéed vegetables over the top. Sprinkle half the cheese over the vegetables.
• Pour and top. Pour the egg mixture over everything. Gently shake the pan to distribute. Top with the remaining cheese.
• Bake. Place in the oven and bake for 28–35 minutes, or until the center is set and a knife inserted in the middle comes out clean. The top should be lightly golden.
• Rest and serve. Let it sit for 5–10 minutes to set. Garnish with fresh parsley or chives, slice into squares, and serve warm.

What Makes This Special

This casserole keeps things simple while delivering big flavor. You get the comfort of eggs, cheese, and sausage, plus a boost of veggies for color and crunch.

It’s naturally low in carbs, so you won’t find bread or potatoes here—just wholesome ingredients that work together. The best part? It reheats beautifully, making it ideal for meal prep and busy mornings.

Whether you’re feeding a crowd or just planning your week, it fits right in.

What You’ll Need

• 12 large eggs
• 1 cup heavy cream (or unsweetened almond milk for lighter)
• 1 pound breakfast sausage (pork or turkey, no sugar added)
• 1 cup shredded cheddar cheese (or a blend like cheddar–Monterey Jack)
• 1 cup bell peppers, diced (any color)
• 1 small yellow onion, diced
• 2 cups fresh spinach, roughly chopped
• 2 cloves garlic, minced
• 2 tablespoons olive oil or butter
• 1 teaspoon kosher salt (plus more to taste)
• 1/2 teaspoon black pepper
• 1/2 teaspoon smoked paprika (optional but great for depth)
• 1/2 teaspoon dried oregano or Italian seasoning
• Chopped fresh parsley or chives for garnish (optional)

How to Make It

1. Preheat the oven. Set it to 375°F (190°C). Grease a 9×13-inch baking dish with olive oil, butter, or cooking spray.
2. Cook the sausage. In a large skillet over medium heat, brown the sausage, breaking it into small pieces. Cook until no longer pink and lightly crispy.

   Drain excess fat if needed and set aside.

3. Sauté the veggies. In the same skillet, add olive oil or butter. Sauté onion and bell peppers with a pinch of salt for 4–5 minutes, until softened. Add garlic and cook 30 seconds.

   Stir in spinach just until wilted. Remove from heat.

4. Whisk the eggs. In a large bowl, whisk eggs, heavy cream, salt, pepper, smoked paprika, and oregano until smooth and slightly frothy.
5. Layer the dish. Spread the cooked sausage evenly in the baking dish. Scatter the sautéed vegetables over the top.

   Sprinkle half the cheese over the vegetables.

6. Pour and top. Pour the egg mixture over everything. Gently shake the pan to distribute. Top with the remaining cheese.
7. Bake. Place in the oven and bake for 28–35 minutes, or until the center is set and a knife inserted in the middle comes out clean.

   The top should be lightly golden.

8. Rest and serve. Let it sit for 5–10 minutes to set. Garnish with fresh parsley or chives, slice into squares, and serve warm.

Keeping It Fresh

Let the casserole cool completely before storing. Slice it into portions, then transfer to airtight containers.

It keeps in the fridge for 4–5 days.

For longer storage, wrap individual slices tightly and freeze for up to 2 months. Reheat in the microwave for 60–90 seconds or in a 350°F (175°C) oven for 10–12 minutes for the best texture. If it looks dry after reheating, a small splash of cream or a sprinkle of cheese before warming can help.

Benefits of This Recipe

• Low in carbs, high in protein: Eggs, sausage, and cheese help keep you full and satisfied.
• Meal-prep friendly: Make it once and enjoy breakfast all week.
• Versatile: Works with many proteins, cheeses, and vegetables without losing its low-carb profile.
• Budget-conscious: Uses common, affordable ingredients and stretches to 8–10 servings.
• Family-friendly: Mild flavors, customizable toppings, and easy to reheat for different schedules.

Common Mistakes to Avoid

• Using raw veggies that release water: Always sauté vegetables first to avoid a watery casserole.
• Overbaking: Dry eggs aren’t fun.

  Pull it when the center is just set and the edges are golden.

• Skipping seasoning: Eggs need salt. Taste your sausage and veggies as you go, and season the egg mixture properly.
• Too much dairy: A little cream adds richness, but too much can prevent it from setting well. Stick to the amount listed.
• Wrong dish size: If your dish is smaller, the casserole will be thicker and need extra time.

  If larger, it will bake faster—watch closely.

Alternatives

• Protein swaps: Try bacon, turkey sausage, diced ham, or leftover rotisserie chicken. For vegetarian, use plant-based sausage or extra mushrooms.
• Cheese options: Pepper Jack for a kick, feta for tang, or mozzarella for a milder, stretchy melt.
• Veggie variations: Mushrooms, zucchini (sautéed well), broccoli florets, or asparagus tips. Keep total veggies around 2–3 cups.
• Dairy-light version: Use unsweetened almond milk instead of cream and reduce cheese slightly.
• Spice profile: Add cumin and chili powder for a Tex-Mex vibe, or use dill and feta for a Greek twist.

  Top with salsa or avocado before serving.

• Mini versions: Bake in a lined muffin tin for portable egg bites. Start checking doneness at 16–18 minutes.

FAQ

Can I make this the night before?

Yes. Assemble the casserole, cover, and refrigerate overnight.

In the morning, take it out while the oven preheats and bake as directed. You may need a few extra minutes if it’s very cold.

How many servings does this make?

In a 9×13-inch dish, you’ll get 8 generous servings or up to 10 smaller ones. It’s hearty, so smaller pieces often go a long way.

Is this keto-friendly?

Yes.

It’s low in carbs and high in fat and protein. If you’re tracking closely, use a no-sugar-added sausage and check your cheese and cream labels.

What’s the best way to reheat without drying it out?

Oven reheating at 350°F (175°C) for 10–12 minutes gives the best texture. Cover loosely with foil.

If microwaving, use 50–70% power and heat in short bursts.

Can I skip the onions or peppers?

Absolutely. Swap them for mushrooms, broccoli, or more spinach. Just sauté well to remove moisture before baking.

Do I need to line the pan?

It’s not required, but greasing the dish well helps with cleanup.

If you prefer, you can line with parchment for easier lifting and slicing.

Can I use egg whites only?

You can, but the casserole will be less rich and may bake up a bit drier. Consider using half whole eggs and half whites for balance.

What toppings go well with this?

Try sliced avocado, hot sauce, salsa, sour cream, or a sprinkle of fresh herbs. A little crumbled bacon on top is great for extra crunch.

Final Thoughts

This low carb breakfast casserole is simple, flexible, and built for real life.

It’s easy to prep, easy to customize, and satisfying any day of the week. Keep the basics the same—good eggs, a tasty protein, sautéed veggies—and make it your own from there. With a pan of this in the fridge, breakfast is one less thing to worry about.