What exactly is a casserole?
It is a slowly cooked mixture of a number of foods, often including meats and vegetables. Pies both sweet and savory are the forerunners of the modern casserole. The word casserole comes from a French term meaning "served in the dish used for cooking." While this does describe the modern casserole, it is much too broad a definition. Today, many meals are served in the same dish they are cooked in, from soups to baked and roasted chicken. To really pinpoint what defines a casserole, a more specific description is needed.
Cakes and other "baked goods" must be excluded, though they can be baked and served from casserole dishes. Cakes and brownies do not maintain the distinction of their various ingredients as they cook; they change to result in a wholly new product.
Dishes like tuna noodle casserole and lasagna are classic and familiar examples of casseroles. They both contain a mixture of ingredients baked together and are served straight out of the baking dish. The ingredients do not meld together in any significant way, remaining mixed, yet separate. Both dishes also hold their shape fairly well when cut, so many think of casseroles as having a high degree of sliceability.
The very popular green bean casserole - a mixture of green beans and cream of mushroom soup, baked and topped with crispy fried onions - shows that sliceability cannot be the defining feature, as the green beans do not make into a solid, easily sliced mass. Instead, they are served in sauce, which is a crucial element of slow cooking and of casseroles. A slowly cooked meal will dry out without moisture being introduced and because casseroles are cooked for fairly long periods of time, a sauce or liquid must be added. The sauce might be largely absorbed during baking, but it is the addition of sauce that is marked here, not what becomes of it.
So, it is not the dish alone that defines a casserole. It does need to be served from the dish it is baked in, but the casserole must have a sauce or liquid added to it before baking and the elements in it must remain distinct.
[Photo by Nicole Weston]