In a large bowl, whisk together the soy sauce, hoisin sauce, honey, rice vinegar, sesame oil, five-spice powder, garlic, ginger, and black pepper until well combined.
Add the chicken thighs to the marinade, ensuring they are fully coated. Cover and refrigerate for at least 2 hours, or overnight for best flavor.
Preheat your grill or oven to 400°F. If using an oven, line a baking sheet with aluminum foil for easy cleanup.
Remove the chicken from the marinade, reserving the marinade for basting.
If grilling, place the chicken on the grill and cook for about 6-7 minutes per side, basting with the reserved marinade. If baking, place the chicken on the prepared baking sheet and bake for 25-30 minutes, basting halfway through.
Cook until the chicken reaches an internal temperature of 165°F and has a nice glaze.
Remove from heat and let the chicken rest for 5 minutes before slicing. Serve with rice or steamed vegetables.