In a mixing bowl, combine minced lemongrass, minced garlic, finely chopped shallot, fish sauce, soy sauce, brown sugar, lime juice, black pepper, and chili paste. Whisk together until well blended.

Add the chicken thighs to the bowl with the marinade, coating each piece thoroughly. Cover with plastic wrap and marinate for at least 30 minutes or up to 2 hours.

Heat a large skillet over medium-high heat and add the vegetable oil until shimmering.

Carefully place the marinated chicken into the skillet. Cook for 5-7 minutes until golden brown, then flip and cook for another 5-7 minutes until fully cooked.

Remove the chicken from the skillet and let it rest for a few minutes. Slice and serve warm, garnished with cilantro and lime wedges.