In a medium bowl, whisk together the soy sauce, brown sugar, honey, gochujang, rice vinegar, sesame oil, minced garlic, and grated ginger until smooth. Add the chicken thighs, ensuring they are fully coated in the marinade. Cover and refrigerate for at least 20 minutes, or up to 2 hours.

In a large bowl, combine shredded green and red cabbage and julienned carrots. In a separate bowl, whisk together mayonnaise, honey, rice vinegar, salt, and pepper. Pour this over the cabbage mixture and toss well. Chill in the refrigerator.

Heat a large skillet over medium-high heat and add oil. Place the marinated chicken thighs in the skillet. Cook for 6-7 minutes on each side until browned and reaches an internal temperature of 165°F.

Using the same skillet, add butter to the cut sides of the buns. Toast them until golden brown and crispy, about 2-3 minutes.

Assemble the sandwich by placing a portion of sliced chicken on the bottom half of each toasted bun, topping with the crunchy slaw, and pressing the top bun down.