Combine the flour, salt and pepper in a plastic bag. Shake the chicken pieces in flour until coated. Heat the oil in a large skillet (one that has a cover/lid). Fry the chicken pieces until they are browned on both sides. Remove from skillet.
Add the onion, garlic and bell pepper to the skillet and saute until the onion is slightly browned. Return the chicken to the skillet and add the tomatoes, oregano and wine. Cover and simmer for 30 minutes over medium low heat.
Add the mushrooms and salt and pepper to taste. Simmer for 10 more minutes.
