In a mixing bowl, combine gochujang, gochugaru, soy sauce, honey, sesame oil, minced garlic, grated ginger, and rice vinegar. Add chicken thighs and marinate for at least 30 minutes.

Preheat your grill or skillet to medium-high heat (about 400°F). Cook marinated chicken for 4-5 minutes on each side until charred and internal temperature reaches 165°F.

In a clean bowl, mix shredded cabbage with mayonnaise and Sriracha until well combined.

Toast brioche buns on the grill or in a toaster until golden brown, about 1-2 minutes.

Assemble the burger with slaw on the bottom bun, followed by the grilled chicken, sesame seeds, and green onion. Cap with the top bun.