Classic Mini Cheeseburgers

1. Make the Sauce

In a bowl, whisk together the mayonnaise, ketchup, sweet pickle relish, sugar, distilled white vinegar, and ground black pepper until well combined. Refrigerate the sauce until ready to use.

2. Prepare the Patties

Divide the ground beef into 12 portions, each weighing about 2 ounces. Roll these portions into balls and then press them into flat patties. Place the formed patties on a baking sheet and cover with plastic wrap. Refrigerate until ready to cook, up to 24 hours in advance.

3. Prepare Buns and Cheese

Spread some of the prepared sauce on the bottom halves of the slider buns. Cut each slice of American cheese into quarters. Set the buns and cheese aside on a platter.

4. Season the Patties

In a small bowl, mix the kosher salt and ground black pepper together. Sprinkle this seasoning mixture evenly over both sides of the patties.

5. Cook the Patties

Heat 1 teaspoon of vegetable oil in a 12-inch nonstick skillet over medium-high heat until shimmering. Add 6 patties to the skillet and sprinkle 1/4 cup of finely chopped onion over them. Press the onions into the patties with a spatula. Cook for about 2 minutes on the first side until well-browned. Flip the patties and immediately top each one with a piece of American cheese. Place the top halves of the buns over the cheese-topped patties. Add 2 tablespoons of water to the skillet and cover with a lid. Cook for about 90 seconds, until the cheese has melted and the buns are slightly steamed.

6. Assemble and Serve

Transfer the cooked patties with their bun tops to the prepared bun bottoms with the sauce. Tent them with aluminum foil to keep them warm. Wipe the skillet clean with paper towels and repeat the process with the remaining patties, onion, cheese, and buns. Serve immediately and enjoy!