Place 0.75 lb ground beef in a bowl. Add 0.5 tsp kosher salt, 0.25 tsp freshly ground black pepper and 0.5 tbs Worcestershire sauce. Gently combine with your hands or a fork—do not overwork the meat. Divide the mixture into 3 equal portions (about 4 oz each). Form each portion into a small, slightly wider-than-the-bun patty, about 3 inches across and 1/2 inch thick. Make a shallow dimple in the center of each patty with your thumb to reduce puffing during cooking.

Cook

Heat a heavy skillet or griddle over medium-high heat and add 1 tsp vegetable oil, swirling to coat. When the pan is hot and just beginning to smoke, add the patties spaced slightly apart. Cook undisturbed 2 to 3 minutes until a brown crust forms on the bottom. Flip and cook another 1.5 to 2 minutes for medium doneness. In the last 30 seconds of cooking, place a quartered cheese slice on each patty, cover pan with a lid to melt the cheese (or tent with foil). Remove patties to a plate and let rest 1 minute.

Buns & Assembly

Prepare buns

Split the 3 mini slider buns. Lightly brush the cut sides with 1 tbs softened butter (or with 1 tsp buttermilk if using for a gloss). Toast cut-side down in a dry skillet over medium heat or under a broiler for 1 to 2 minutes until golden and slightly crisp. Watch carefully to avoid burning.

Assemble sliders

Spread 1 tsp mayonnaise on the bottom half of each toasted bun. Spread a small amount of ketchup and 1/3 of the mustard across the three bottoms (approximately 2 tsp ketchup and 1 tsp mustard divided). Place a lettuce pinch on each bottom bun, then place a cheeseburger patty on top. Add two pickle slices and a few thin red onion rings to each slider. Cap with the top bun. If desired, secure each slider with a small toothpick.

Toppings & Sauce

If using hot sauce, mix 1 tsp into the mayonnaise before spreading for a spicy mayo. Taste and adjust ketchup/mustard ratio if you prefer sweeter or tangier. Serve sliders immediately while warm.

Optional

For a glossy finish, brush the tops of buns lightly with 1 tsp buttermilk or melted butter after toasting. If preparing ahead, keep patties warm in a low oven (200°F / 95°C) for up to 15 minutes before assembling.