In a medium baking dish, mix the eggplant, onion, garlic, green bell pepper, mushrooms and olive oil.
Cook covered 10 minutes in the preheated oven.
Remove the eggplant mixture from the oven and stir in the water, sliced stuffed green olives, salt, tomato paste, red wine vinegar, sugar, basil, oregano and pepper.
Continue baking 30 minutes, or until the eggplant is tender.
Chill the mixture in the refrigerator 8 hour or overnight before serving.