Cut chicken thighs into little pieces or slice them thinly so they will cook very quickly and absorb marinades.
Whisk together gochujang, soy sauce, ginger, garlic, sesame oil, black pepper, brown sugar, and optional mirin and corn syrup in a bowl.
Marinate Chicken - Overlap one chicken over the marinade and the chicken in the marinade. The optimal marinating flavor is 2 hours (marinate the chicken overnight at refrigeration level); 15–20 minutes will taste better.
Cook the Chicken - Place a pan over medium-high and oil within it. Heat and then add the marinated chicken in a single layer. Cook for 4–5 minutes on each side, turn, and cook the other 4–5 minutes, or golden brown, caramelized, and cooked.
Garnish and Serve - Serve the chicken bulgogi and garnish with slices carrot, sesame seeds and spring onion or fresh mint leaves. Serve steaming hot over steamed rice, lettuce wraps, or as a Korean dish.
