Pound chicken flat; set aside. In butter, sauté shallots; add mushrooms and sauté 2 to 3 minutes. Add wine and lemon juice; let simmer 6 to 7 minutes. Dredge chicken in flour and season if desired. Sauté in oil in frying pan. Add cream to mushroom mixture and heat until reduced. On warm serving plates, place mushrooms over chicken breasts. Sprinkle with chopped parsley and serve immediately.