How to Make It
In a mortar, pound the lemongrass with the ginger, jalapeños and garlic, then add the brown sugar and pound to a paste. Stir in the fish sauce and the 2 tablespoons of oil. Rub the paste all over the chicken and refrigerate for at least 2 hours or up to 6 hours.
Light a grill or preheat a grill pan. Brush the chicken with oil and grill over high heat, turning once, until lightly charred outside and cooked through, about 5 minutes. Serve with rice, lime wedges and chopped cilantro.