The head chef is an employee of your restaurant in Cafe World. He is in charge of cooking dishes on the stoves and then transferring the cooked dishes on free counters so they can be served by waiters.
You are the head chef of your Restaurant and your character should reflect that! If you are unhappy with your appearance at any time, you can easily change it by clicking on the shirt icon from the lower left hand menu (in between your cookbook and the decoration buttons). This brings up the customization screen where you can easily modify skin color, facial features, hair and eyes as well as purchase new clothes and accessories with your hard earned Cafe Coins! You can also edit your character by clicking it in game.
Only you can be the head chef of your restaurant, and unlike waiters, you can not choose any of your Facebook friends to take that position.