The Mexican diet is based on some very specific aliments: beans, corn, tomatoes, chilies and exotic fruits. Corn is the most important aliment and the oldest one, as it has been consumed for over 4000 years and today it is used for the famous tortillas, tacos, tamales and nachos and beans are prepared as kidney beans and fava (is soups or stews), served as refrito or de la olla. The tomatoes are essential for the salsas and the dips, used for the fish meals or the beef ones. Chilies are used both dried and fresh and they are found in a wide range: chipotle, haberano, mulato, cascabel or serrano. In central Mexico, there is a mixture of Spanish and Aztec cuisines: nuts, different spices, cocoa and seeds are very much used. In the south, peppers are mostly used dry, especially in stews and toppings. The best sauce for the seafood, famous on the Pacific coast, is the achiote sauce, which is also added to chicken or pork.