In a medium-sized bowl, combine the finely chopped lemongrass, minced garlic, and chopped red chilies. Add the fish sauce, soy sauce, sugar, vegetable oil, and black pepper. Whisk vigorously until well combined.

Take your boneless, skinless chicken thighs or breasts and add them to the bowl with the marinade. Ensure each piece is thoroughly coated. Cover with cling wrap and refrigerate for at least 30 minutes, preferably 1-2 hours.

Preheat your grill or a non-stick skillet over medium-high heat for about 5 minutes. Ensure it’s clean and lightly oiled.

Remove the marinated chicken from the refrigerator and let excess marinade drip off. Place the chicken on the preheated grill or skillet. Cook each side for 6-7 minutes, or until golden brown and cooked through (internal temperature should reach 165°F/75°C).

Once cooked, carefully remove it and allow it to rest on a cutting board for about 5 minutes.

Slice the rested chicken into strips and arrange on a platter, showcasing the grill marks.

Top the slices with freshly chopped cilantro and serve with lime wedges on the side.