Preheat grill pan or broiler to high heat. While heating, dice tomatoes and place in a bowl with minced garlic, torn basil, 2 tablespoons olive oil, salt, and pepper. Mix gently and let marinate.

Brush bread slices lightly with remaining olive oil on both sides. Grill or broil until golden brown and crispy, about 2-3 minutes per side.

Remove bread from heat. While still warm, rub one side of each slice with the whole garlic clove.