Preheat the grill to medium-high heat. Season the chicken breasts with Italian seasoning, garlic powder, onion powder, and sprinkle with salt and pepper on both sides.
Spray the grill with non-stick cooking spray, then cook the chicken breasts until they are nearly fully cooked.
Place a slice of mozzarella on top of each chicken breast. Close the grill and cook for a few more minutes until the cheese is melted.
Remove the chicken from the grill and top with sliced tomatoes and basil. Drizzle with the homemade balsamic reduction and serve immediately. Enjoy!
Balsamic Reduction:
In a small saucepan, combine balsamic vinegar and brown sugar. Simmer for 10 minutes or until the sauce has reduced by half. Keep warm until ready to use.