Place large plates in 2 steamer baskets and arrange the scallops on the plates in a single layer so that the shells don’t overlap.
Half fill a wok or large saucepan with water and bring to the boil.
Meanwhile combine soy sauce, shao xing, vinegar, water, sesame oil, grated ginger and sugar and stir well to dissolve sugar. Spoon ½ teaspoon sauce over each scallop. Place steamer over wok or saucepan, cover and steam for about 1 minute, then swap baskets around and steam for a further minute or less, until scallops are just opaque (they should still be glassy in the centre).Remove the basket from the wok, arrange scallop shells on plates. Drizzle with remaining sauce, sprinkle with green onions and sesame seeds and serve immediately.
Shao xing and Chinese black vinegar are available from Asian grocery stores. Shao xing is Chinese cooking wine, if it is unavailable substitute dry sherry. Toast sesame seeds in a dry frying pan for a couple of minutes, tossing gently to prevent them burning.Recipe supplied by FISHline, Sydney Fish Market’s free consumer advisory service. Visit the FISHline pages at www.sydneyfishmarket.com.au for more great seafood recipes, advice on seafood purchasing, storage and cooking, species information and answers to frequently asked seafood questions.