Cut stem end off eggplant. Dice eggplant into small cubes. Sprinkle eggplant with salt and place in a colander to drain. Let sit for 15 minutes. Squeeze as much liquid out as possible.
In a small bowl, combine soy sauce, sugar, vinegar and water.
Heat 1 TB dry sherry in a large skillet or wok. Add crushed red pepper and stir. Add ginger, white part of scallion. Stir fry briefly until ginger becomes fragrant. Add the squeezed eggplant and saute approximately 8-10 minutes, stirring occasionally, until eggplant is thoroughly cooked. You shouldn't have any trouble with sticking because the eggplant still has a bit of moisture in it but if it does, add a little bit of water or sherry.
Add soy sauce mixture and cook over high heat until most of the liquid is evaporated and eggplant is thoroughly coated with reduced sauce – about 5 minutes.
Combine water and cornstarch.
Add chopped green part of scallions and water/cornstarch. Stir and cook until thick. Serve hot over plain rice.