In a small saucepan, heat the balsamic vinegar with the honey over medium high heat.  Bring the mixture to a boil.  Then reduce the heat to a low simmer.

Simmer for approximately 10 minutes until the mixture has been reduced in half. Remove from heat.

Place the chicken breasts in a bag or bowl.  Pour half of the balsamic mixture over top of the chicken and allow it to marinade for at least 30 minutes (or overnight).  Reserve the other half of the mixture for serving.

Preheat the grill over medium high heat (approximately 400 degrees F).

Put the vegetable oil onto the griddle and use your spatula to spread it around.

Then place the filleted, marinated chicken breasts on the griddle and season them with the garlic powder, salt and pepper.

Allow them to cook for 4-6 minutes until browned. Flip the chicken, cook for 5-6 more minutes until the chicken reaches an internal temperature of 165 degrees F.

Remove the chicken from the griddle.

Let the chicken rest for 5 minutes.

While the chicken is resting.  Butter both sides of the ciabatta buns.  Place them cut side down on the grill and cook for 1-2 minutes to brown them slightly.

They layer the chicken, mozzarella chicken, tomatoes and basil onto the buns.  Drizzle the reserved balsamic mixture on top and then the sandwiches are ready to serve and enjoy!