HEAT grill to medium-high heat.
MIX meat and 1/4 cup dressing; shape into 12 (1/4-inch-thick) patties. Top with cheese slices and remaining patties. Pinch edges together to seal.
GRILL 5 min. on each side or until done (160°F). Meanwhile, mix tomatoes, garlic, basil and remaining dressing.
FILL buns with lettuce, burgers and tomato mixture.