1Make the pickles by combining sliced cucumbers, vinegar, salt, pepper, mustard, and sugar in a container and letting them sit in the refrigerator.
2Press the ground beef out onto a parchment-lined baking sheet and season with salt and pepper.
3Brush the flattened ground beef patty with yellow mustard.
4Slice the Hawaiian rolls in half.
5Top the raw beef patty with the prepared pickles and diced white onion, then layer with slices of American cheese.
6Apply a mixture of yellow mustard and mayonnaise to the bottom half of the sliced Hawaiian rolls.
7Assemble the slider by placing the bottom bun, topped with the beef patty, pickles, onions, and cheese, on the baking sheet, then top with the second half of the buns.
8Cut the assembled slider block into individual sliders and serve.