Score the fish, gently making three to four cuts along the body of the fish on both sides, starting from the dorsal n to the belly. The cuts should be deep enough that you can stuff them with some ginger and onions. Sprinkle the salt in the slits on both sides to help flavor the fish. Gently place half of the onions and 1⁄4 cup of the ginger into the slits.
In a small pot over medium-high heat, combine the soy sauce, wine, oil, and the remaining onions and 1⁄4 cup ginger. Heat to a boil and then reduce the heat to low. Keep the sauce over low heat while the fish steams.
Place the fish in a steam-proof dish, such as a pie plate, that fits in your steamer. The dish should be deep enough to let the sauce pool at the bottom. Steam the fish for 10 to 15 minutes, depending on the size of the fish. To check for doneness, turn off the heat. Carefully lift the lid of the steamer. Using the tip of a sharp knife, gently probe the flesh at the meatiest part of the fish. If it is opaque and flakes, then the fish is done steaming. If it looks underdone, then close the lid and steam over high heat for up to 5 minutes more.
Remove the dish from the steamer and drizzle the soy sauce mixture over the sh. Garnish with cilantro. Serve with rice as a part of a meal.
Hsiao-Ching Chou is the author of "Chinese Soul Food: A Friendly Guide for Homemade Dumplings, Stir-Fries, Soups and More." She lives in Seattle with her family. Text her cooking questions via her messaging service: 206-565-0033.