ROLL-CUT THE CHINESE EGGPLANTS or, if using the regular large variety, trim and cut them into 1-inch cubes. Sprinkle the cubes with salt and leave in a sieve to drain for 20 minutes, then rinse under cold running water and pat them dry with paper towels. Heat a wok or large skillet to a moderate heat. Add the oil and let it heat up for a few seconds, then add the eggplant, garlic, ginger and scallions and stir-fry for 1 minute, until they are thoroughly mixed together. Now add the rest of the ingredients except for the scallions. Turn the heat down and cook, uncovered, for 10 to 15 minutes, until the eggplant is tender, stirring occasionally. Return the heat to high and continue to stir until the liquid has been reduced and has thickened slightly. Turn the mixture onto a serving dish and garnish with the chopped scallion tops.