POUND chicken to 1/4-inch thick. Mix flour, 1/2 tsp. of the salt and 1/4 tsp. of the pepper in small shallow bowl.
HEAT oil in large skillet over medium heat several minutes. Coat chicken with flour mixture; shake off excess and place in skillet. Cook 4 minutes; flip chicken and continue cooking 4 to 5 minutes or until cooked through (165ºF). Remove to plate; keep warm.
ADD mushrooms to skillet; cook over medium-high heat 5 minutes or until mushrooms are golden brown and liquid has evaporated, stirring frequently. Season with remaining 1/4 tsp. each salt and pepper. Add wine; simmer 2 minutes or until reduced by about half. Add broth; simmer about 5 minutes or until sauce is slightly reduced. Add butter; stir until melted. Top with chicken; continue cooking several minutes to heat through. Top with parsley.
Use dry white wine for Marsala.
Use boneless skinless chicken breast halves for thighs.