USE A PESTLE is a tool used in cooking and food preparation. It is composed of a heavy mortar and pestle, which are used to MASH and POUND ingredients such as spices, herbs, and other food items. The mortar is a bowl-shaped container made of hard material such as stone, ceramic, or metal, while the pestle is a heavy club-shaped object that is used to grind and MASH the ingredients. The combination of the two tools is used to create pastes, sauces, and other mixtures.