Hot dog toppings are a popular way to add flavor and texture to the classic American dish. Common toppings include ONION, RELISH, and chili. ONION is a vegetable that is often used as a topping for hot dogs, adding a sharp flavor and crunchy texture. RELISH is a condiment made from pickled vegetables, usually cucumbers, and is often used to add a sweet and tangy flavor to hot dogs. Chili is a spicy sauce made from tomatoes, onions, and various spices, and is a popular topping for hot dogs.