The casserole, from the Greek word "kyathos," meaning bowl, is one of the most useful cooking tools in the kitchen, and especially in a professional kitchen, there can be no shortage of them in various versions: with one handle or two handles and in various heights, high or deep, half-deep (or half-high) and low. For it to be called a casserole, its diameter must be greater than its height, otherwise it takes the name pot. For a casserole to be called tall or deep, it must have a height that exceeds half the diameter, while in the mezzofonda, the height corresponds exactly to half the diameter, and it goes without saying that the shallow casserole (which is also called "rondeau") will have a height less than half the diameter. Casseroles are very ductile tools to cover a wide range of uses. The most usual cooking to be practiced in a casserole are stewing and braising for which a high casserole is generally used, poaching and glazing which will be optimized in a half-deep casserole, and sautéing for which a low casserole will be perfect and which can possibly be replaced by a frying pan. Casseroles are also sold with a lid that must ensure a perfect seal, which is essential for long cooking that needs to maintain its moistness. Stews are also called "mixed cooking" because they often involve a first browning phase and a second long cooking by immersion in a liquid: sauce, wine or other. Because of all these articulated uses, almost any food can be cooked in a casserole, although the most usual use is for stewing meats of various kinds and vegetables. There are several materials most suitable for the production of casseroles. Tinned copper, or internally coated in stainless steel, is definitely the noblest material for casserole cooking because it is an exceptional conductor of heat and is therefore suitable for both fast and long cooking and especially perfect for the most delicate cooking such as, for example, risotto where the difference is precisely the perfect homogeneity of cooking. Other excellent materials for the production of casseroles are aluminum and nonstick aluminum, or stainless steel, which is more suitable for long cooking. There is a wide range of commercially available sizes, including oval-shaped ones, which are very useful for cooking whole pieces of meat or fish.