There's a big difference between fresh abalone and the dried stuff. While the latter is very expensive to buy and time-consuming to prepare, fresh abalone is reasonably priced (although not exactly cheap) and it cooks quickly. They are not difficult to clean, but if you want, have the vendor clean them for you, although this should be done as close as possible to the time you're going to cook them.
Prepare the abalone. Use a sharp paring knife to cut the muscle that attaches the abalone to the shell. Use a clean toothbrush to scrub the entire surface of the abalone under cool running water. Squeeze the abalone to remove the liver, then rinse thoroughly.
Slice the ginger about 3mm (⅛in) thick. Cut the spring onions into 5cm (2in) lengths.
In a small bowl, mix together the oyster sauce, soy sauce, rice wine and sugar. Put about two heaped tablespoons of cornstarch in another bowl and add about 60ml of cool water (the exact amounts don't matter because you won't need all of the cornstarch mixture; it's used to thicken the sauce).
Heat a wok over a high flame and add about 60ml (¼ cup) of cooking oil. When the oil is very hot, add the spring onions and stir-fry very quickly, so they are slightly blistered but still bright green. Scoop the spring onions from the wok, leaving behind most of the oil, and drain the pieces on paper towels.
Heat the oil again, add the ginger and stir-fry constantly for about 30 seconds, until the slices are slightly browned and blistered. Scoop the ginger from the wok and drain on paper towels. Pour off all but about 15ml (1tbsp) of cooking oil from the wok.
Place the wok over a medium-high flame. When it's hot, add the abalone and the ginger and stir-fry briefly, then stir in the sauce mixture. Lower the heat, cover the wok with the lid and simmer the ingredients for about two minutes, or until the abalone is almost cooked.
Remove the lid and turn the heat to medium-high. Stir the cornstarch/water mixture, then drizzle some of it into the wok while constantly mixing the ingredients in the wok. Add just enough cornstarch so the sauce lightly coats the abalone and ginger.
Stir in the spring onions and cook for about 30 seconds. Transfer the ingredients to a serving dish and serve immediately.