Prepare the marinade by combining Gochujang, soy sauce, sesame oil, honey, ginger, and garlic in a glass mixing bowl.
Incorporate chicken cutlets into the marinade, ensuring total surface coverage, and refrigerate for 15 minutes.
Produce the slaw by mixing shredded cabbage, chopped kimchi, Kewpie mayonnaise, and rice vinegar in a separate container.
Place a heavy-bottomed non-stick skillet over medium-high heat (approx. 200C).
Sear the chicken cutlets for 3 to 4 minutes per side until the sugars in the marinade have caramelized and the internal temperature reaches 74C.
Slice the brioche buns and toast the interior surfaces until golden brown.
Assemble the sandwiches by layering equal portions of cooked chicken on the bottom bun, followed by a generous layer of kimchi slaw, and the top bun.