Begin by trimming any excess fat from the chicken thighs, ensuring a leaner cut. Use a meat mallet to pound the thighs to an even thickness of about 1 inch.

In a large resealable bag or bowl, combine zesty lime juice, neutral oil, soy sauce, fish sauce, brown sugar, minced garlic, fresh grated ginger, and red chili flakes.

Add the prepared chicken thighs into the marinade, sealing the bag tightly or covering the bowl. Refrigerate for at least 30 minutes to let the flavors infuse into the meat.

While the chicken marinates, preheat your grill to medium-high heat, targeting a temperature around 400°F (204°C).

Carefully place the marinated chicken thighs on the hot grill, cooking them for about 3-5 minutes on each side. Flip the chicken only once.

Once the chicken has finished grilling, remove it from the heat and let it rest for about 5 minutes. Garnish with fresh cilantro and sliced green onions before serving.