Cut eggplant into 1/2 inch slides, sprinkle with a little salt on both sides (to draw out water), and let slices drain in colander for 30 minutes. While eggplant is draining, cook the onion in 1 tb olive oil over moderate heat, stirring until golden; stir in garlic, tomatoes, oregano and wine and simmer, stirring occasionally, for 10 minutes, or until liquid is almost evaporated. Stir in the Parmesan cheese, parsley and salt and pepper to taste; transfer the topping to a bowl, cover and keep warm.
Brush salt from surfaces of eggplant, rinse quickly and pat dry. In the skillet, heat the remaining olive oil until hot, but not smoking and cook the eggplant, browning on one side, then turn, reduce heat, and cook an additional 5 minutes or more until tender. Transfer to plate, spoon the tomato and onion topping onto it, and serve with additional cheese.