This Keto Low-Carb Egg Breakfast Casserole is packed with protein, veggies, and cheese, this delicious dish is perfect for meal prep or feeding a crowd. This casserole is not only easy to make but also the perfect meal-ahead dish for meal planning, allowing you to enjoy a hearty, guilt-free breakfast with cheese, spinach, and peppers throughout the week. Serve this dish for your holiday breakfasts and brunch!