In a large bowl, whisk together the balsamic vinegar, honey, garlic, extra virgin olive oil, salt, pepper and Italian seasoning.
Add boneless chicken breasts to bowl making sure they are coated in the marinade . Let sit for 30 minutes.
Stir avocado, tomato, basil, and a pinch of salt and pepper together in a small bowl.
Grill marinated chicken on high heat for 6 minutes each side or until the chicken is cooked through.
Top grilled chicken with mozzarella cheese slices and avocado mix.
If desired, drizzle a bit more balsamic vinegar on top.
Enjoy!