Keto Breakfast Casserole

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Keto breakfast casserole is full of protein, savory flavors, and easy ingredients! Made with fluffy eggs, green and red peppers, spinach, mushrooms, and two types of cheese, this easy breakfast recipe is the best ever. Low-carb and perfect for the whole family.

Perfect for busy mornings, this low-carb breakfast casserole recipe is so delicious and easy to make. This keto egg bake recipe is great for whenever you need inspiration for new low-carb breakfasts. One of the main reasons why I love this low-carb recipe is because it is so versatile and can be customized with any vegetables you have!

The whole family will enjoy this healthy breakfast casserole and you can make it ahead or bake in a muffin tin for on-the-go mornings. The eggs are whisked with heavy cream for extra fluffiness and then poured over a colorful array of nutritious vegetables to create one of the best keto breakfast recipes.

Save this easy recipe if you are looking for a breakfast casserole without bread or new keto breakfast ideas that only have a few minutes of prep time! Made with simple ingredients, you will want to make this recipe again and again because it is so yummy and cheesy! 

👩🏽‍🍳 Why You’ll Love This Keto Breakfast Casserole

• Keto-Friendly And Low-Carb: This low-carb egg casserole without meat has just 3 g of net carbs per serving so it is a good option for someone who follows a keto diet or low-carb lifestyle.
• Easy for Meal Prep: Make the casserole ahead of time to save time the next morning. Leftovers taste even better the next day so make one casserole and have breakfast ready for the whole week.
• One-Pot Recipe: Just one pot and a casserole dish are needed so this is an easy cleanup recipe and is also great for potlucks, busy days, or dropping off to a friend.
• Family-Friendly: This is the perfect recipe for the whole family. Hearty keto breakfast casserole will keep you full all morning and kids will love the melty cheese. The vegetables add so much flavor to this easy gluten-free egg casserole with no meat.
• Great Anytime Of The Year: This keto egg casserole recipe uses ingredients that are available year-round and can be made with all frozen vegetables so you can make this casserole on short notice or when feeding a crowd for a weekend brunch, Thanksgiving, or Christmas morning.

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🥘 Ingredients

You can find the ingredients for this low-carb vegetarian casserole at your local grocery store! See the recipe card below for exact ingredient amounts, nutritional information, and detailed instructions.

• Eggs: These are the key ingredients to bind this low carb no meat breakfast casserole together! I prefer to use large eggs.
• Mushrooms: Button mushrooms are versatile, neutral in flavor, and a great way to add extra protein to this keto breakfast casserole recipe.
• Frozen Spinach: Thaw and remove the liquid before using.
• Bell Peppers: I used both green bell peppers and red bell peppers in this delicious recipe.
• Red Onion: Red onion has a nice onion flavor and adds a beautiful purple hue to this colorful casserole.
• Heavy Cream: Heavy whipping cream is mixed with the eggs to make the keto casserole fluffy and rich.
• Olive Oil: I use both liquid and spray oil to cook the vegetables and coat the baking dish so the casserole doesn’t stick.
• Garlic: Adds flavor to all the veggies and eggs.
• Shredded Cheese: Shredded cheddar cheese and feta make the best-tasting egg and cheese casserole with no meat! Grating your own cheese offers the best flavor and will melt to be the creamiest.
• Salt and Pepper: Simple salt and black pepper enhance the flavors of this casserole.

🍲 Ingredient Substitutions

• Oil: Use any type of neutral cooking oil like coconut oil or avocado oil to prevent the low carb egg bake from sticking to the casserole dish.
• White or Yellow Onion: You can use yellow or white onions in place of red onion.
• Garlic Powder: If you don’t have fresh garlic, garlic powder can be used to add garlic flavor.
• Peppers: Use your favorite color or combination of red, orange, yellow, or green bell peppers. You can use fresh peppers or frozen mixed bell peppers.
• Cream Alternatives: In place of heavy cream, use half and half, whole milk, low-fat milk, or a lactose-free or dairy-free milk alternative such as unsweetened almond milk, but this low carb breakfast bake will not be as rich.
• Fresh Spinach: Wash, dry, and chop fresh spinach and substitute for the frozen spinach.
• Cheese: Use pre-shredded cheddar cheese, white cheddar cheese, parmesan cheese, Pepper Jack cheese, mozzarella, cottage cheese, or your favorite shredded block of cheese. Combine one or more cheeses for a mixed cheese and egg breakfast casserole.

🔪 How To Make Keto Breakfast Casserole

Here’s how to make this easy keto breakfast recipe. See the recipe card for full measurements and instructions.

Sauté Vegetables: Preheat the oven to 350 degrees Fahrenheit. Heat the oil in a large skillet over medium heat, then add the diced onion. Cook for two to three minutes or until translucent. Be careful not to burn the onion! Next, add the garlic, bell peppers, and mushrooms. Cook until all the vegetables are soft and remove them from the heat.

Mix Eggs: In a large mixing bowl, whisk together the eggs, cream, salt, and pepper. Mix until everything is fully combined.

Transfer to Baking Dish: Grease a 7×11-inch casserole dish with nonstick spray so the eggs do not stick to the sides. Drain the excess liquids from the cooked vegetables and spread an even layer into the bottom of the dish.

Layer: Next, layer the thawed and drained spinach on top of the vegetables and pour the egg mixture over them.

Bake: Top the eggs with feta and cheddar cheese. Then, bake this easy keto breakfast casserole in the preheated oven for 30-45 minutes until cooked through completely. The center should not be able to wiggle when shaken and the color of the casserole should be golden brown.

Cool: Remove the casserole from the oven and allow it to cool for ten minutes.

Serve: Cut the casserole into 12 individual servings and enjoy!

💭 Expert Tips

• Drain the cooked vegetables: To prevent the casserole from becoming too watery, drain the cooked vegetables before adding them to the casserole dish. 
• Defrost and remove excess water from the frozen spinach: The best way to remove excess water from frozen spinach is to defrost the spinach in a strainer and then squeeze it with your hands or use paper towels to press it until you’ve removed most of the moisture. Separate it with a fork because it will become compacted when squeezed.
• Grease casserole dish well: For the easiest serving, spray the dish well with oil or grease with butter. A well-greased dish will allow you to easily remove slices and not leave any of the good stuff behind due to sticking. 
• Use what you have: This is one of the most versatile breakfast recipes ever so don’t feel like you need to have exact ingredients. Make this casserole with almost any vegetable combination, so I love using what I have on hand and filling up this casserole with leftover veggies I need to use!

📖 Variations

• Extra Spicy: Adjust the heat to your personal preferences by adding red pepper flakes on top of the casserole before baking, ¼ teaspoon of Cayenne pepper to the eggs, or serve this dish with your favorite hot sauce.
• Additional Protein: To keep this a vegetarian keto casserole, you can add plant-based spicy sausage or breakfast sausage to this recipe for a sausage breakfast casserole. Just cook it with the onion and peppers and break it into small pieces with a wooden spoon as it cooks, then add the vegetable and sausage mixture to the casserole dish! If you eat meat, you can increase the grams of protein per serving with Italian sausage or ground sausage to make a keto sausage egg casserole.
• Egg Muffins: For breakfast egg muffins, follow the recipe as stated and use muffin tins for individual servings that are easy to reheat and freeze well. Transfer the egg mixture into an oiled 12-cup muffin pan. Preheat the oven to 350 degrees Fahrenheit and bake the muffins for 15 to 20 minutes. If you follow a low-carb diet or ketogenic diet, individual portions are an easy way to track your carbohydrate intake.
• Garnish: Before serving, garnish this easy low-carb breakfast casserole with freshly sliced green onions or fresh parsley.

🍽 Serving Suggestions

Enjoy by itself or serve with other breakfast foods. The casserole is filling on its own and has lots of nutrient-dense vegetables so it can stand alone or serve it with additional items. I like serving this low-carb breakfast casserole with fiber-rich smoothies, salads, and other favorite breakfast recipes for a larger spread. You can also serve it with a small serving of fruit for the kids!

🙌 Dietary Adaptions

This casserole is already vegetarian, gluten-free, and happens to be a diabetic friendly breakfast casserole recipe too! To make it into a dairy-free egg casserole, omit the cheese and use dairy-free milk in place of the heavy cream.

🫙 Storage Directions

• Storing: Leftovers keep in an airtight container in the refrigerator for up to four days.
• Reheating: Reheat this low carb vegetarian breakfast bake in a preheated oven at 350 degrees Fahrenheit for about 15 minutes. When heating from frozen, allow this dish to thaw overnight in the refrigerator.
• Freezing: Freeze leftovers for up to three months. Wrap individual pieces in plastic wrap or aluminum foil before placing them in a freezer-safe container.

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📋 Recipe Card