Whisk together balsamic vinegar and honey until combined to form your marinade. Add the marinade and chicken pieces to a large ziplock bag or mixing bowl, and toss until combined. Seal/cover and refrigerate to marinate for at least 10 minutes, or up to 8 hours. Also, if you are using wooden skewers, set them to soak in a pan of water for at least 10 minutes so that they do not burn.

When you are ready to cook the chicken, heat a grill to medium-high heat. Remove the chicken pieces from the marinade, reserving the marinade for later, and thread chicken onto skewers. Season the skewers generously with salt and pepper. Place on a grill that has been lightly greased with cooking spray. Cook the chicken skewers for 3-4 minutes per side, turning once, until the chicken is no longer pink inside and cooked through. Remove chicken skewers from grill and place on a serving plate.

Meanwhile or after, pour the reserved marinade into a small saucepan and bring to a boil over high heat. Reduce heat to medium-low and simmer for about 12 minutes, or until the mixture is reduced by half and is thick enough to coat the back of a spoon. (The glaze will thicken even more as it cools.) Remove from heat, and brush the glaze onto the skewers until they are all evenly coated. Serve warm.