Flat, solid griddles are a principal technology in the Mexican kitchen. Round like disks, comales are made of clay, tin, iron or steel. In predominantly indigenous communities they are placed on three stones that represent the center of the house. Although they are largely used to cook or heat tortillas, they are also used to toast, grill or fry.
Materials and forms vary according to intended use and region. For instance, enchiladas placeras from Michoacán are fried on tin griddles with a slit in the center that holds oil; discadas in the northern highlands are prepared on a steel griddle adapted from a thresher disk. If they are not glazed, clay comales must be "seasoned" with lime or ashes. They are ideal for grilling tortillas, tlacoyos, gorditas and other corn snacks, as well as for toasting spices, seeds and cocoa beans; amaranth is roasted with the aid of an escobeta, a small brush. Other foods can be cooked on the coals beneath the comal, such as seafood tamales; and in some regions, a crook-legged clay jar known as a patojo, for heating liquids, is placed beneath the comal’s three supporting stones.