The Aztecs made great guacamole. Well, actually, it was ahuacamolli—literally, "avocado mixture"—which they concocted by tossing buttery, nutty chunks of avocado with green chiles, tomatoes, and fresh local herbs. Today, most guacamoles also include minced white onion and cilantro, though some Mexican cooks add tomatillos or even finely sliced zucchini. For the most part, guacamole has remained simple in its homeland, where it's generally served as a garnish for other dishes—not as an appetizer with chips. Our favorite guacamole (in America at any rate) comes from Josefina Howard, co-founder of Rosa Mexicano in New York City, who advised following the Aztecs' lead: use a molcajete (mortar) made of volcanic stone, and keep it simple—additional ingredients just muddle it up.