Chef wiki:
so executive chef or chef de cuisine), from the French for chief or head person, is the executive in charge of a kitchen, responsible for recipe and menu creation, staff training, and overseeing all cooking. A chef directs the staff of cooks, bakers, butchers, and everyone else involved in the preparation of food. The duties of chefs are to plan the menu, determine the price and how much it will cost to make the dish. Cooks and chefs are on their feet throughout their work day, and during mealtimes must work under pressure. They face such hazards as cuts and burns, and may be exposed to oily mists, dusts, fumes, and smoke.
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