01 - Combine gochujang, soy sauce, sesame oil, honey, rice vinegar, garlic, ginger, brown sugar, and black pepper in a large bowl. Mix thoroughly until well incorporated.
02 - Add chicken pieces to the bowl and toss to coat evenly. Cover and let marinate for at least 15 minutes, or up to 2 hours for deeper flavor penetration.
03 - Heat a large skillet or grill pan over medium-high heat until properly heated.
04 - Shake excess marinade from chicken pieces and arrange in a single layer in the hot pan. Cook for 5–7 minutes per side, turning occasionally, until chicken is cooked through and develops caramelized edges.
05 - Pour remaining marinade into the pan, reduce heat to medium, and simmer for 2–3 minutes until sauce reduces and thickens, coating the chicken pieces.
06 - Transfer chicken to a serving platter. Sprinkle with sliced green onions and sesame seeds. Serve immediately with steamed rice or desired sides.