MAKE THE SPREAD: In a small bowl, mix together the mayonnaise, relish, ketchup, sugar, and vinegar. Set aside.
PREPARE TOPPINGS OF CHOICE: Slice raw onions, tomatoes, and pepperoncini peppers. Tear off pieces of iceberg lettuce.
OPTIONAL - MAKE CARAMELIZED ONIONS: Dice 1 large onion finely. In a saute pan, cook onions with vegetable oil and salt until golden brown, then add water until translucent. Set aside.
PREPARE THE PATTIES: Portion and shape the ground beef into patties, season with salt and pepper. Set aside.
TOAST THE BUNS: Brush butter on the buns and toast until golden brown.
COOK THE PATTIES: Cook patties in butter and vegetable oil, adding mustard and cheese.
ASSEMBLE THE PATTIES: Spread sauce on the buns, add toppings, then place the patty and cheese, followed by more toppings and the top bun. Enjoy!
