Tacos can include a wide variety of ingredients, such as beef, pork or chicken, fish, shrimp, beans, and vegetables. This allows for versatility and variety. Many tacos are garnished with salsa, guacamole, or sour cream, as well as vegetables like lettuce, onions, tomatoes, and chiles. Tacos can include a wide variety of ingredients, such as beef, pork or chicken, fish, shrimp, beans, and vegetables. This allows for versatility and variety. Many tacos are garnished with salsa, guacamole, or sour cream, as well as vegetables like lettuce, onions, tomatoes, and chiles.