Combine olive oil, balsamic vinegar, minced garlic, fresh rosemary, thyme, paprika, salt, pepper, lemon juice, and Dijon mustard in a large bowl. Whisk thoroughly until the marinade emulsifies into a cohesive, fragrant mixture that will coat each piece evenly.
Add chicken pieces to the marinade bowl and toss until every surface is thoroughly coated. Cover with plastic wrap and refrigerate for at least fifteen minutes, though thirty minutes yields deeper flavor development.
Thread marinated chicken pieces onto skewers, alternating with bell peppers, red onion chunks, mushrooms, and cherry tomatoes for visual appeal and even cooking throughout. Leave slight gaps between items to allow heat circulation and prevent steaming instead of grilling.
Preheat your grill to medium-high heat, approximately 400-425°F, and lightly oil the grates to prevent sticking. Place cozy labor day grilled chicken kebabs recipe portions on the hot grill, spacing them about two inches apart.
Grill for 8-10 minutes on the first side without moving, allowing those beautiful char marks to develop. Rotate each skewer carefully and grill the opposite side for another 8-10 minutes until the chicken reaches an internal temperature of 165°F.
Transfer finished kebabs to a clean platter and let them rest for five minutes before serving to allow juices to redistribute throughout the chicken and vegetables.