Heat olive oil in non-stick skillet and fry until golden on all sides. Remove chicken as you fry it and put it into an oven proof casserole or baking pan.
In the same skillet add the onion and garlic to the olive oil and fry until golden. Add the mushrooms (drained if using canned).
Then add the tomato sauce and white wine. Add more salt and pepper to taste, oregano and parsley. Cook over medium heat until well blended, about 20 minutes.
Add pitted black olives. Pour sauce over the chicken pieces. Cover and bake in a 350 degree oven for about one hour.