As we visited markets and kitchens across Mexico while putting together our Mexico issue, we received an invaluable education in the ingredients and equipment that give Mexican cooking its singular intensity and depth of flavor. When we began to test recipes back in the SAVEUR kitchen, we found that all these workhorses of the Mexican kitchen are readily available in the United States, at Latin American markets and through mail order. Get to know these basic elements, and you'll be well on your way to grasping the art and ingenuity behind one of the world's great cuisines.