Casseroles are a key component to family cooking. Easy assembly, baking and serving make casseroles a favorite of busy moms and party throwers. The ease continues the next day because leftovers can be effortlessly reheated revealing even better flavors. That's because both meat and potatoes form a gelatin layer as they cool. These layers act as a sponge for the other components of the dish, soaking up a delectable collage of flavors. And casseroles keep well in the refrigerator or the freezer. And reheating is a breeze -- cover and reheat in the microwave, stirring or rotating the dish several times during the process to help ensure even heating.