Begin by placing the boneless skinless chicken thighs in a large bowl. Add soy sauce, brown sugar, minced garlic, grated ginger, lime juice, turmeric powder, and chili powder. Stir everything together until the chicken is well coated. Cover the bowl with plastic wrap and let it marinate in the refrigerator for at least 30 minutes, preferably overnight for deeper flavor absorption.

After marinating, heat a tablespoon of oil in a skillet over medium-high heat. Once the oil is shimmering, add the marinated chicken thighs, ensuring they are not overcrowded. Sear each thigh for about 6-8 minutes on each side until they acquire a golden-brown color.

Once the chicken is seared, pour in the coconut milk, ensuring it coats the chicken evenly. Reduce the heat to medium and let the mixture simmer. Cover the skillet and cook for about 20 minutes until the chicken is cooked through and tender.

Once the chicken is cooked, remove the thighs from the pan and let them rest. If you prefer a thicker sauce, continue to simmer the coconut milk mixture uncovered for an additional 5-10 minutes.

After the sauce has reached the desired thickness, return the chicken to the skillet briefly to coat with the sauce. Arrange the chicken thighs on a serving platter and garnish with fresh coriander. Serve with steamed rice or noodles.