This Overnight Omelette Breakfast Casserole is a delicious and convenient dish that can be prepared the night before and baked in the morning. Made with eggs, milk, cheese, vegetables, and your choice of meat, this casserole is hearty, flavorful, and perfect for feeding a crowd. The overnight refrigeration allows the flavors to meld together, resulting in a savory and satisfying breakfast option that requires minimal effort in the morning.