
Rub the mackerel fillets with the sake or rice wine. Set aside for about 4-5 minutes, then pat dry.
Mix together all ingredients for the marinade except the chopped cilantro. Rub the marinade over the fillets and set aside at room temperature for about 10-15 minutes.
While marinating the fish, preheat your grill pan (or outdoor grill) over medium heat. Once it is hot, oil the grates.
Shake off excess aromatics on the mackerel and then cook on the grill until just cooked through, about 3 minutes each side. Adjust cooking time as needed and avoid overcooking the fish.
Sprinkle chopped cilantro over the flesh side of the mackerel fillets. Remove from the grill and serve right away.