1. Pre-heat oven to 350°F (175°C).
2. Heat olive oil in heavy casserole and fry chicken breasts until browned from both sides.
3. Add onions, tomatoes, herbs, salt and white wine and place in pre-heated oven. Cook for one hour and fifteen minutes.
4. Take from oven, remove chicken. Stir in sour cream and add freshly ground black pepper to taste.
5. Serve with boiled potatoes, pasta or rice.