Preheat the grill to medium-high heat.
In a mixing bowl, whisk together honey, barbecue sauce, olive oil, garlic powder, onion powder, salt, and pepper to create the marinade. Reserve half of the sauce for basting.
Place chicken breasts in a shallow dish and pour half of the marinade over them. Allow the chicken to marinate for at least 15 minutes (or longer in the refrigerator if time allows).
While the chicken is marinating, prepare the grilled veggie medley. In a bowl, toss the sliced bell pepper, zucchini, red onion, and cherry tomatoes with olive oil, Italian seasoning, salt, and pepper.
Once marinated, remove the chicken from the dish and place it on the grill. Grill for about 6-7 minutes on each side, basting with the reserved marinade during the last few minutes of cooking.
At the same time, place the seasoned vegetables on the grill. Grill for 5-7 minutes, stirring occasionally, until they are tender and slightly charred.
Remove the grilled chicken and vegetables from the grill. Let the chicken rest for a few minutes before slicing.
Serve the honey BBQ chicken alongside the grilled veggie medley.