Prepare the Marinade. In a bowl, whisk together Gochujang, soy sauce, honey, minced garlic, grated ginger, rice vinegar, sesame oil, chopped green onions, and sesame seeds until well combined.
Marinate the Chicken. Place the chicken thighs in a shallow dish or resealable plastic bag. Pour the marinade over the chicken, making sure each piece is well coated. Cover or seal and refrigerate for at least 1 hour, or ideally overnight, to allow the flavors to meld.
Air Fryer Instructions. Preheat your air fryer to 375°F. Remove the chicken thighs from the marinade, shaking off any excess, and place them in the air fryer basket in a single layer, skin side up. Cook for 20-25 minutes, flipping halfway through, until the chicken is cooked through and the skin is crispy and golden brown.
Serve and Enjoy. Remove the chicken thighs from the air fryer or oven and let them rest for a few minutes before serving. Garnish with additional chopped green onions and sesame seeds, if desired.