Tostadas, a type of Mexican food, are corn tortillas served either fried, toasted, or baked and covered with a variety of different toppings. Typical toppings on tostadas are refried beans, guacamole, beef, cheese, chicken, lettuce, onion, salsa, or tomato. They are very similar to tacos except that they are usually left flat rather than folded in half. On most occasions, they are served as a main dish.