Stewing or casseroling implies long slow moist cooking with a measured quantity of liquid in a pan or casserole with a tight-fitting lid. Cooking can be done either on top of the cooker or in the oven. Either way the liquid should simmer gently and never boil, since this toughens the meat. The amount of liquid used should be such that the flavours and nutrients extracted from the meat and any added vegetables are retained and served in a gravy with no waste. A small quantity of liquid can be used, provided the pan has a tight-fitting lid. There will be only a small amount of evaporation and little risk of scorching, if the cooking is gentle.