01 - Preheat a grill pan or skillet over medium-high heat until evenly hot.
02 - Gently combine ground beef with salt, pepper, and garlic powder in a mixing bowl. Divide mixture into 8 equal portions and shape into patties slightly larger than the buns to account for shrinkage.
03 - Place patties on the hot cooking surface and cook for 2–3 minutes per side until browned and reaching desired doneness.
04 - During the final minute of cooking, top each patty with a cheese slice and cover the pan to melt completely.
05 - Lightly toast slider buns cut-side down on the grill or in a toaster until golden brown.
06 - Spread mayonnaise, mustard, and ketchup evenly on the bottom half of each toasted bun.
07 - Place a cheese-topped patty on each prepared bun base. Add 2 pickle slices per slider along with optional onion and lettuce. Crown with bun tops and serve immediately.