Marinate Chicken: In a mixing bowl, whisk together soy sauce, brown sugar, honey, gochujang, rice vinegar, sesame oil, garlic, and ginger until smooth. Add the chicken thighs, ensuring they’re fully coated in the marinade. Cover and let marinate for at least 20 minutes at room temperature, or up to 2 hours in the refrigerator.

Prepare Cabbage Slaw: In a large bowl, combine cabbage with carrots. In a separate bowl, whisk together mayonnaise, sugar, and a splash of rice vinegar until well blended. Pour the dressing over the cabbage mixture and toss to combine. Cover and chill for about 15 minutes.

Cook Chicken: Preheat your grill or skillet over medium-high heat. Remove chicken from marinade and grill or pan-sear for 6-7 minutes per side, or until the internal temperature reaches 165°F (74°C). Let rest for a few minutes before slicing.

Toast Buns: Melt butter in a skillet over medium heat. Spread a layer of butter on the insides of the buns and toast them for about 2-3 minutes until golden brown.

Assemble Sandwich: Place sliced grilled chicken on the bottom half of a toasted bun, drizzle with leftover marinade if desired, add the slaw on top, and cap with the top bun.