If using wooden skewers, place in a bowl or shallow plate filled with 1 inch of water and soak for 20 minutes. If using metal skewers, set aside.
Bring balsamic vinegar to medium heat in a small saucepan and cook for 20 minutes or until reduced by half.
The vinegar is just right when it coats the back of a spoon. Cover with a lid and keep warm.
In another small saucepan, add the extra virgin olive oil and the garlic cloves and cook over medium heat for 10 minutes or until the oil becomes fragranced with garlic.
Remove from heat and brush both sides of the bread slices with the garlic infused oil. Cut the bread into 1-inch cubes.
Thread the skewers starting with a cube of bread, then cheese, then tomato and a basil leaf and repeat another time, ending with a cube of bread. Repeat with the rest of the skewers.
Give each skewer another generous dab of the olive oil and then a sprinkle of kosher salt and freshly ground black pepper.
Bring grill to high heat.
Place skewers on grill rack and cook for 4 minutes or so, turning skewers every 30 seconds to 1 minute. .
When the tomatoes begin to blister, the bread starts to toast, cheese is melty, and all sides are cooked evenly remove from the grill.
Drizzle with reduced balsamic. *If balsamic reduction begins to thicken, heat again over medium heat and stir until thinned.
Serve and enjoy!