1Divide 85g of 85/15 ground beef into four equal balls. Place them in the refrigerator to chill.
2Prepare the sauce by mixing 1/3 cup of light mayo, 2 tbsp of Dijon mustard, 1-2 tbsp of hot sauce, 1 tbsp of pickle relish with some juice, and 1/4 cup of grated yellow onion.
3Heat a cast iron pan over medium-high heat.
4Place two beef balls into the hot pan and flatten them using a meat smasher.
5Season the patties with salt and pepper.
6Cook the patties for 2-3 minutes per side, then flip them and top with a slice of cheddar cheese each.
7Toast the hamburger buns.
8Assemble the burgers by layering the patties, lettuce, tomato, and sauce on the toasted buns.