In a large mixing bowl, whisk together the fish sauce, soy sauce, brown sugar, minced garlic, grated ginger, vegetable oil, honey, black pepper, and chili powder until smooth.

Coat the chicken thighs in the marinade, ensuring each piece is covered. Cover the bowl or transfer to a resealable bag and refrigerate for at least 1 hour or overnight.

Preheat your grill to medium-high heat (about 400°F or 200°C) for 15 minutes before grilling.

Remove the chicken from the marinade, allowing excess to drip off, and place on the grill. Cook for 5-7 minutes per side until charred and internal temperature reaches 165°F (75°C).

Transfer the chicken to a plate and let it rest for about 5 minutes to redistribute juices.

Garnish with cilantro and serve with lime wedges for added flavor.