The Mexican mortar and pestle were traditionally made out of volcanic rock, and used for grinding and pulverizing spices and vegetables, and for making guacamole.
In some areas of Mexico a molcajete is also the name of a great lunch dish - a friend came across this on a recent trip to Acapulco. Cactus, carne asada steak strips, chorizo, cheso malena, and whole baby onions are served in a traditional mortar with tortillas for wrapping. The meat was seasoned with spices, and blackened to perfection. Red and green salsa and pico de gallo (not recommended for travelers!) was served on the side. This was listed as the "Specialty of the house" for the Metates restaurant on the main drag in downtown Acapulco.
Bonus Word of Mouth: The Spanish word Metate refers to a tool used for grinding grain and seeds in Meso-American cultures, that is thought to be a precursor to the mortar, in those areas.
(Image credit: Mike Durand)