Preheat your oven to 350°F (175°C) and use a 9×13-inch baking dish coated with non-stick spray. For the best flavor, choose Vidalia sweet onions, peeling and slicing them into ¼-inch rounds.

Season with salt, garlic powder, and oregano. This dish is versatile and pairs well with grilled meats, barbecued chicken, or classic sides. Bake for 35-40 minutes until the cheese is bubbly and browned. You can mix cheeses like Italian blend, cheddar, and Parmesan, or add crumbled bacon or sausage for a heartier dish.