This Cheesy Mushroom & Sausage Breakfast Casserole is a delicious and hearty dish that is perfect for breakfast or brunch. It is made with sautéed mushrooms, savory sausage, and a creamy cheese sauce. The casserole is then topped with a layer of melted cheese and baked until golden and bubbly. It is a crowd-pleasing recipe that can be prepared ahead of time and reheated for a quick and easy breakfast option. Serve it with a side of fresh fruit or a green salad for a complete meal.