Pound the chicken breasts until they are approximately 1/2 inch thick.

Add all the marinade ingredients to a mixing bowl.  Whisk the ingredients together until fully combined.

Place the chicken breasts in a ziplock bag and place the sliced peppers and onions in a separate bag.

Pour part of the marinade over the pepper and onions until they are fully coated with the marinade.

Pour the remaining marinade over the chicken.

Let the chicken, peppers and onions marinade for at least 30 minutes or up to 8 hours (overnight).

Preheat a grill over medium high heat (approximately 350 degrees Fahrenheit) and rub the grill grates with 1 tablespoon of the olive oil.

While the grill is preheating, cook the peppers and onions.  Heat the remaining olive oil in a large skillet over medium high heat.

Add in the marinated peppers and onions. Cook, stirring occasionally, for 8-10 minutes until the vegetables start to brown.

Add a small amount of water to the pan and continue to cook for 3-4 more minutes until the water cookies off and the vegetables are tender.  Remove from heat.

Place the chicken on the grill.  Cook for 3-4 minutes per side until the chicken reaches an internal temperature of 165 degrees Fahrenheit.  Be careful not to overcook.

Remove from heat, let the chicken sit for at least 10 minutes.

Slice the chicken.  Serve with the peppers and onions and enjoy!