Chicagoans are very particular about their hot dogs. To begin with, it has to be an all-beef product, served on a steamed poppy seed bun. But just as important are the essential toppings. If you walk into a proper Chicago hot dog stand and order it "Chicago Style," you'll get exactly these seven ingredients on your dog: yellow mustard, chopped white onions, neon green pickle relish, a dill pickle spear, tomato wedges, sport peppers and, of course, celery salt.