01 -
Heat 2 tablespoons unsalted butter in a skillet over medium-high heat. Add the chopped onion and cook until soft and caramelized, about 5-7 minutes. Remove from the skillet and set aside.
02 -
Add ground beef to the same skillet over medium-high heat. Season with salt, pepper, smoked paprika, and garlic powder. Cook, breaking apart with a spatula, until browned and cooked through. Drain excess fat.
03 -
Slice King's Hawaiian rolls in half horizontally. Spread a thin layer of mayonnaise on the cut sides.
04 -
Place the rolls, cut side down, in a clean skillet over medium heat. Toast until golden brown. Remove and set aside.
05 -
Preheat oven to 175°C. Lightly grease a baking dish or sheet pan. Arrange the bottom halves of the toasted rolls, cut side up, in the dish. Layer half of the American cheese slices over the rolls, top with cooked ground beef, then the caramelized onions, followed by remaining cheese slices. Place the top halves of rolls, toasted side up, to complete the sandwiches.
06 -
Transfer to the oven and bake for 10 minutes, or until the cheese is thoroughly melted and rolls are lightly crisp.
07 -
In a bowl, combine mayonnaise, ketchup, mustard, and sweet relish to prepare the burger sauce. Serve sliders warm with burger sauce for dipping.