In a medium bowl, combine the tomatoes, garlic, basil, olive oil and balsamic vinegar. Add salt and pepper to taste and set aside.
Add 1-2 tablespoons of olive oil to a large skillet and preheat over medium-high heat. Season the chicken with oregano, salt and pepper on both sides and add to the skillet. Saute for 4-5 minutes per side until golden brown and the internal temperature of the chicken reaches 165 degrees.
Sprinkle a small amount of mozzarella cheese on each breast and cover the skillet until it melts.
Place the chicken on a plate and top each breast with bruschetta topping. Drizzle with a little more balsamic vinegar if desired.
