Combine flour  and pepper. Between two pieces of plastic wrap pound chicken pieces lightly to 1/4 inch [1 cm] thickness. and sprinkle with salt to taste. Coat chicken pieces with flour mixture.

 In a skillet heat butter over medium-high heat, sauté mushrooms until brown.  Remove mushrooms and set aside.  Add olive oil and heat until very hot.  Reduce heat to medium and cook the chicken halves  about 2 to  3 minutes on each side or till golden brown and no pink remains.

 Add Marsala and chicken stock. Bring to boil, reduce heat and simmer, uncovered,  for 3 to 4 minutes, add the sautéed mushroom and parsley.  Simmer for 1 more minute.  Serve