In a medium bowl, add the chopped cilantro, fresh lime juice, olive oil, garlic powder, soy sauce, sugar, salt, and pepper. Whisk well until everything is fully combined and smooth.

For the best flavor and texture, use mostly cilantro leaves and remove thick stems before chopping.

Place the chicken breasts or thighs into a resealable plastic bag or a shallow dish. Pour the prepared marinade over the chicken, making sure each piece is evenly coated.

Seal the bag or cover the dish and refrigerate for at least 30 minutes. For deeper flavor and more tender chicken, marinate for 2–4 hours.

Preheat your grill to medium-high heat. Remove the chicken from the marinade and place it directly on the hot grill.

Cook for about 6–7 minutes per side, or until the internal temperature reaches 165°F (74°C) and the chicken is fully cooked.

Remove the chicken from the grill and let it rest for a few minutes before slicing. Resting helps the juices settle back into the meat, keeping the chicken tender, juicy, and full of flavor.