Mix together the oil, soy sauce, ginger, and sherry. Sprinkle over the salmon and let it marinate for 15 minutes.
Prepare to steam. Fill the bottom of a large wok or saucepot with 3 inches of water. Place a steamer rack in the wok or pot. Place the fish fillets on a heat proof plate. Cover the wok or pot and steam the fish for 10 minutes, until it is tender.
Sprinkle the fish with lime peel and scallions. Serve with lime wedges.