1. In shallow dish, combine flour, salt, pepper and oregano; stir to blend.
2. In heavy skillet, heat oil and butter until butter melts and mixture bubbles lightly.
3. Dredge chicken in seasoned flour; shake off excess; saute in pan 2 minutes for the first side or until lightly browned; as you turn chicken, add mushrooms around the chicken pieces. Cook about 2 more minutes, until lightly browned on the second side; stir mushrooms. Once the second side is lightly browned, add wine around the pieces; cover and simmer for 10 minutes.
4. Transfer to plates and serve.