In a medium bowl, whisk together soy sauce, brown sugar, honey, gochujang, rice vinegar, sesame oil, minced garlic, and grated ginger until smooth. Add the chicken thighs, ensuring they are well-coated. Cover the bowl and let them marinate at room temperature for 20 minutes or refrigerate for up to 2 hours for deeper flavor before cooking.

In a large mixing bowl, combine shredded green and red cabbage with grated carrot and diced green onions. In a separate bowl, whisk together mayonnaise, rice vinegar, and a pinch of salt until blended. Pour the dressing over the cabbage mixture and toss until everything is evenly coated. Chill in the refrigerator while you cook the chicken.

Preheat a skillet or grill over medium-high heat. Once hot, add the marinated chicken thighs and cook for about 6-7 minutes per side until charred and cooked through.

While the chicken rests, split the buns and spread butter on the cut sides. Toast the buns in the skillet or grill until golden and crisp.

To assemble the sandwich, layer sliced grilled chicken, drizzle with extra BBQ sauce, top with the crunchy cabbage slaw, and place the top bun on.