In a medium bowl, whisk together the bourbon, soy sauce, brown sugar, apple cider vinegar, garlic, ginger, black pepper, and red pepper flakes.
Add the chicken pieces to the marinade, ensuring they are well coated. Cover and refrigerate for at least 1 hour, or up to 4 hours for more flavor.
Preheat your grill to medium-high heat. If using wooden skewers, ensure they have soaked in water to prevent burning.
Thread the marinated chicken pieces onto the skewers, leaving a little space between each piece for even cooking.
Brush the grill grates with vegetable oil to prevent sticking. Place the skewers on the grill and cook for about 10-12 minutes, turning occasionally, until the chicken is cooked through and has nice grill marks. The internal temperature should reach 165°F.
Remove the skewers from the grill and let them rest for a few minutes before serving. Serve with your choice of dipping sauce or over rice.