While you can visit a hot dog spot in NYC and get plenty of toppings, a traditional New York-style hot dog uses a specific combo.

Mustard, sauerkraut, and a unique type of tomato-heavy onion relish are must-haves. The mustard can be either yellow or spicy brown, depending on who you ask.

The mustard's sharpness and the pickled cabbage's refreshing tartness offset the hot dog's meaty, fatty, and salty flavors.

What sets New York-style hot dogs apart is the onion relish. The seasonings in this relish differ from recipe to recipe, containing onions, a tomato product, and cinnamon.

Once the ingredients are cooked down and the onions are soft, the relish takes on a dark red or brown hue. It is mildly sweet and vinegary and goes well with other toppings.