Sprinkle the chicken with salt and pepper. Heat the olive oil in a heavy frypan and brown the chicken on all sides. Remove the chicken and set aside. Add the onion, bay leaf, rosemary and sage then saute until onions are soft, about 5 minutes.
Add garlic and cook 30 seconds more. Return the chicken to the frypan and add wine. Cook over medium heat until the wine has evaporated, stirring. Add the tomatoes and chicken stock, reduce heat, cover and simmer 25 minutes.
Add the olives and mushrooms and cook 10 more minutes. Taste for seasoning.