A casserole is a dish that is cooked slowly in the oven, typically in a deep, wide pan. It often combines various ingredients such as meats, vegetables, grains, and sauces, all baked together to create a hearty meal. Casseroles are popular for their convenience, as they can be prepared in advance and are easy to serve. Casseroles can vary widely in flavor and ingredients, with some classic examples including green bean casserole and lasagna. They are often associated with comfort food and are commonly served at family gatherings and potlucks, making them a staple in many households.