Process of preparation of foods by mixing, combining and heating the ingredients. Heatactivated cooking methods take five basic forms. Food may be immersed in liquids such as water, stocks, or wines ( boiling, poaching, stewing); immersed in fats or oils (frying); exposed to vapour ( steaming and, to some extent, braising); exposed to dry heat (roasting, baking, broiling); and subjected to contact with hot fats (sauteing). Cooking fats Fatty substances such as butter, margarines and vegetable shortenings which are solid at room temperature and are used to moisten, enrich, tenderize and flavour foods during cooking.