Pound the chicken just enough to even it out; do not pound it thin.
Brush chicken with olive oil and season with salt and pepper.
Place the chicken breasts on the grill over direct heat and cook for 6 minutes.
Turn it over and continue to cook for another 8 to 10 minutes; check for doneness. Chicken is done when temperature reads 160°F.
In the meantime, prepare the salsa; combine the fruit, onions, cheese, and basil in a mixing bowl. Season with salt and freshly ground black pepper to taste.
Add olive oil and toss together.
Remove the chicken and let rest for 5 minutes.
Top the chicken with the salsa and drizzle with balsamic vinegar.