Add the oil and garlic to a small saucepan set over a cold burner. Turn the heat to medium and poach the garlic until it is browned and crispy. Remove from heat and cool.  Reserve the garlic oil.

Cut the tomatoes into a small dice. Add to a colander and rinse, washing away the seeds and tomato water. Transfer to a bowl. Add 1 teaspoon of the garlic oil, pesto, and balsamic vinegar. Season with cracked black pepper. (These two steps may be done ahead.)

Turn on all grill burners to high. Brush one side of each bread slice with garlic oil. (Save any extra oil for another use). Flip each slice over and add cheese to the un-oiled side. Top half of the bread with the tomato mixture. Set the bread on the grill, oiled side down. Close the cover and grill 30 seconds. Turn the bread 90 degrees to get crossed grill lines. Cover and cook another 30 seconds. Remove from heat.

To prepare the sandwiches, flip a piece of cheesy bread onto each piece of bread with tomatoes. Gently press down on the top of each sandwich to help the cheese layers melt together.