Poke the skin side of the chicken thighs all over with a meat tenderizer or fork. This helps prevent the skin from shrinking and makes it extra crispy when cooked.

Place the chicken skin-side down in a skillet (no oil needed for nonstick; use a little oil for cast iron) and cook over medium heat. Once the skin is crispy, flip and cook the other side.

Blot excess fat with a paper towel, add the char siu sauce, and bring to a simmer. Adjust sweetness with sugar to taste, then finish by stirring in the butter. Serve and enjoy!