01 - Whisk together soy sauce, brown sugar, sesame oil, garlic, ginger, gochujang, rice vinegar, sesame seeds, and black pepper in a bowl until well combined.
02 - Add chicken thighs to the marinade, turning to coat thoroughly. Cover and refrigerate for 30 minutes to 2 hours for optimal flavor penetration.
03 - While chicken marinates, slice the carrots, cucumber, cabbage, and avocado. Cook rice if not already prepared.
04 - Combine mayonnaise, gochujang, rice vinegar, and honey in a small bowl. Mix until smooth and set aside for serving.
05 - Heat grill pan or skillet over medium-high heat. Cook marinated chicken thighs for 5-6 minutes per side until internal temperature reaches 165°F and char marks develop.
06 - Transfer cooked chicken to cutting board and let rest for 5 minutes. Slice into strips across the grain for maximum tenderness.
07 - Divide rice among four bowls. Arrange sliced BBQ chicken, carrots, cucumber, purple cabbage, and avocado on top.
08 - Drizzle generously with gochujang mayo. Sprinkle with sliced green onions and sesame seeds. Serve immediately while warm.