In a medium-sized mixing bowl, combine the soy sauce, honey, rice vinegar, minced garlic, grated ginger, sesame oil, and black pepper. Whisk these ingredients together until well blended to create a flavorful marinade.
Transfer the chicken thighs into a large resealable zip-top bag or a shallow dish. Pour the prepared marinade over the chicken, ensuring every piece is well-coated. Seal the bag tightly or cover the dish with plastic wrap, and refrigerate for at least 30 minutes. For an even more robust flavor, marinate for up to 4 hours.
Preheat your oven to 400°F (200°C) while the chicken is marinating.
Prepare a baking dish by lining it with parchment paper to facilitate easy cleanup. Remove the chicken from the marinade, setting aside the marinade for later use.
Arrange the marinated chicken thighs in the lined baking dish in a single layer. Bake in the preheated oven for 20 minutes.
While the chicken is baking, pour the reserved marinade into a small saucepan. Heat over medium heat until it comes to a boil, then reduce the heat and let it simmer gently for about 5-7 minutes, or until it thickens slightly.
After baking for 20 minutes, carefully remove the chicken from the oven. Use a baster or spoon to coat the chicken with some of the thickened marinade. Place the dish back in the oven and continue baking for an additional 10-15 minutes, or until the internal temperature of the chicken reaches 165°F (75°C).
Once fully cooked, allow the chicken to rest for a few minutes before slicing. Drizzle any remaining thickened marinade over the sliced chicken for added flavor.
For the finishing touch, garnish your dish with the finely chopped green onions and a sprinkle of sesame seeds just before serving.
Notes
For best flavor, marinate the chicken for up to 4 hours.