Preheat the oven to 425º. In a small bowl, combine the cilantro with the garlic, scallions, ginger, lemon zest, salt and pepper. On a sturdy baking sheet, spread a sheet of heavy-duty aluminum foil large enough to wrap loosely around the fish. Sprinkle one-third of the cilantro mixture lengthwise down the center of the foil. Set the fish on the mixture and sprinkle another third on top. Drizzle the lemon juice over the fish and fold up the foil sides and ends, forming a loose but well sealed packet. Bake the fish for 40 minutes, or until cooked through.
Meanwhile, in a small saucepan, combine the olive oil with the soy sauce and vinegar and warm over moderate heat.
Carefully open the fish packet and pour off the juices. Transfer the fish to a large platter and sprinkle with the remaining cilantro mixture. Pour the sauce over the fish and serve at once.