A Chicago-style hot dog is a unique type of hot dog that originates from Chicago, Illinois. It features an all-beef frankfurter served in a poppy seed bun. This hot dog is known for its distinctive toppings, which include yellow mustard, chopped onions, sweet pickle relish, a slice of tomato, a dill pickle spear, and sport peppers. One key aspect of a Chicago-style hot dog is that it is never topped with ketchup, as this is considered a culinary faux pas in the city. The combination of flavors and textures makes it a beloved street food and a staple at local ballparks and restaurants.