Makes 3 burgers
For the burger:
Season the patties with salt and pepper. Grill to desired temperature (medium is recommended). Melt the cheddar on the patty. Slightly toast the brioche and warm the onions. Build your burger. First place the pickles, then the patty with the cheese, the onions, and on the top bun smear about 2 tablespoons of the comeback sauce.
For the comeback sauce:
Fold together all of the ingredients. Season with salt and pepper. Refrigerate until use.