Prepare the Marinade : In a large mixing bowl, combine the minced garlic, fish sauce, oyster sauce, white pepper, ground turmeric, and brown sugar. Mix well until the sugar dissolves and the marinade is smooth.

Marinate the Chicken : Add the chicken thighs to the bowl, ensuring they are fully coated with the marinade. Massage the marinade into the chicken for even flavoring. Cover the bowl with plastic wrap and refrigerate for at least 2 hours or overnight for the best flavor.

Cook the Chicken : Preheat your grill to medium heat. Place the chicken skin-side down on the grill and cook for 6–8 minutes until the skin is golden and crispy. Flip and cook for another 12–15 minutes, or until the internal temperature reaches 165°F (74°C). Heat a large skillet over medium heat and add a small amount of oil. Cook the chicken skin-side down for 6–8 minutes until the skin is crispy. Flip and cook for another 12–15 minutes until fully cooked. Preheat your oven to 375°F (190°C). Place the chicken thighs on a lined baking sheet and bake for 35–40 minutes, turning halfway through, until the chicken is cooked through and golden brown.

Rest and Serve : Allow the chicken to rest for 5 minutes after cooking. Serve hot with steamed jasmine rice, a fresh salad, or Thai dipping sauce for a complete meal.