Heat up the prepared chili via microwave or stovetop.
Dice the red onion and tomatoes. Shred cheese, if necessary.
Grill the hot dogs using desired cooking method.
To assemble each hot dog, place on a potato roll then top with 1/4 cup prepared chili, 1 T diced onion, 1 T diced tomato, 1 Oz. shredded cheese, and a squirt of mayonnaise.