Many of the foods that are popular today in Peru have been dietary staples in the region for thousands of years and include potatoes, corn, squash, chili peppers, avocados and fish. Potatoes, which are served in a wide variety of dishes in Peru, were grown there long before the Spanish conquistadors first brought them back to Europe during the 1500s. Because of the Humboldt Current that flows off Peru's Pacific Coastline, there is also a great abundance of fish, and ceviche, which consists of raw fish marinated in citrus juice, is practically a national dish.
Peru claims to have developed hundreds of varieties of potatoes and the country is also known for its avocado crop. These two local staples are often combined in a casserole known as "causa." The dish can also contain eggs, tuna or meat and is served cold. Much of the Peruvian cuisine is spicy and is a combination of indigenous and Spanish food. These dishes are usually referred to as Criolla."
Peru's three contrasting geographical regions, which consist of the tropical Amazon rainforest to the east, the highlands of the Andean region and the Pacific coast, have contributed to an equally diverse variety of local menus. The western coastal region has numerous seafood dishes that are served with the abundant national crops of potatoes, rice and corn. The highland area diet is not very different from what the Incas ate prior to the Spanish colonization. Meats, soups and stuffed corn dumplings called "tamales" are often augmented in the Andean region with trout freshly caught in Lake Titicaca, the highest lake in the world. The menus of the eastern tropical region of Peru consist of fresh fruits, vegetables and meats along with plenty of plantains and rice.