Place a large skillet over medium-high heat with 2 turns of the pan of EVOO, about 2 tablespoons. (You could also preheat a grill pan or a large nonstick skillet over medium high heat or, preheat outdoor grill instead of the skillet).
While the pan is heating up, combine the meat with about 3 tablespoons of grated red onion, Worcestershire, grill and poultry seasonings or salt and pepper. Form two-inch meatballs, then flatten them into patties.
Cook the mini burgers for 3 minutes on each side then top with cheese. Tent the mini cheeseburgers loosely with foil to help the cheese melt.