Recently I observed patrons at a sushi bar separately tipping the sushi chef and the server who brought drinks, soup, cooked dishes, etc. This made me feel awful, as I've always just left a single tip, assuming that there is a restaurant policy for splitting the tip. Does anyone know if that is the case? Should a sushi chef be tipped separately from the server -- if so, do you just note separate tips on a credit card receipt? Does it matter whether you are sitting at the sushi bar?