Step 1To make the marinade, combine the soy sauce, Shao-Hsing wine or sherry, two tablespoons of scallion oil, ginger, sesame oil, vinegar, salt and pepper in a medium bowl. Set aside.
Step 2Wash the fish well inside and out. Make 3 cuts with a sharp knife in the side of the fish, cutting to, but not through, the bone. Repeat on the other side. Dry the fish well with paper towels and place it in a steamproof dish. Pour the marinade over the fish and rub it in with your hands on both sides, making sure to rub it well into the cuts. Set aside to rest for 10 to 15 minutes.
Step 3Place a rack in a wok, add boiling water, place the steamproof dish with the fish on the rack and cover. Steam for 15 to 20 minutes. Turn off the heat and transfer the fish to a serving platter. Pour one tablespoon of the hot scallion oil and the accumulated marinade over the fish, sprinkle with the scallions and cilantro and serve immediately.