Place eggplant in a single layer in a bamboo steamer basket over a saucepan or wok of boiling water and steam until limp and wrinkled (15-20 minutes). Cool and cut into chunks and chill or keep at room temperature.
For roasted sesame dressing, combine ingredients in a bowl and stir until sugar dissolves. Just before serving, pour dressing over eggplant, toss lightly to coat, scatter with sesame seeds, coriander and garlic chives and serve immediately.
Note If using Mediterranean eggplant, halve lengthways, sprinkle cut-side lightly with salt and stand for 30 minutes. Rinse and dry using absorbent paper before steaming. Roasted sesame seeds are available from Asian grocers. Alternatively, you can dry-roast sesame seeds in a pan until light golden. Roasted sesame paste is a Chinese-style sesame paste that is available from Asian grocers.