Combine gochujang, rice vinegar, soy sauce, and toasted sesame oil to create a marinade.
Marinate the chicken thighs in the mixture for a period of time to absorb the flavors.
Preheat the broiler in your oven.
Place the marinated chicken thighs under the broiler.
Broil until the edges are charred and the marinade has thickened into a sticky glaze that adheres to the chicken.
