In a medium bowl, whisk together gochujang, soy sauce, honey, sesame oil, minced garlic, grated ginger, rice vinegar, and black pepper to prepare the marinade.

Place chicken thighs in a resealable bag or bowl, pour the marinade over, coat evenly, and refrigerate for at least 1 hour.

In a large bowl, combine shredded cabbage and julienned carrots for the slaw.

In a small bowl, whisk mayonnaise, lime juice, and sriracha, then add to the cabbage and carrot mixture and toss well.

Preheat grill or grill pan over medium-high heat for about 5 minutes and lightly oil to prevent sticking.

Grill marinated chicken thighs for 6-7 minutes per side until nicely charred and cooked to 165°F (75°C).

Slice grilled chicken thighs into strips for easy assembly.

Toast brioche burger buns until golden brown, about 2-3 minutes.

Assemble the sandwiches by layering each bottom bun with sliced grilled chicken, topping with slaw, cilantro, and sesame seeds.