Put the fish into a shallow dish.Stir together all of the remaining ingredients and pour over the fish.Cover with plastic wrap and chill for at least 2 hours, as long as 8 hours.Remove the fish from the marinade and grill over a hot grill for 10 to 15 minutes, or just until cooked through.Turn once.Garnish with lime slices and cilantro sprigs.Serves 6.