Heat grill to 375 degrees F. and oil grates if needed. Drizzle Avocado oil onto chicken breasts, then season with the Tastefully Simple Rustic Herb Seasoning.
Grill chicken for 5 to 7 minutes per side, or until cooked through (165 degrees F). Cover chicken loosely with foil and let rest for 5 to 10 minutes.
For the Balsamic Glaze
Meanwhile add balsamic vinegar and brown sugar to a small saucepan over medium high heat. Bring mixture to a low boil, then reduce heat to medium low. Cook on a low simmer for 6 to 8 minutes, or until glaze is thick enough to coat the back of a spoon. Remove glaze to a glass jar and let cool.
Serve the chicken sliced with the slices of fresh mozzarella, tomato and basil. Drizzle the balsamic glaze over the top and enjoy!