Put chicken breasts between two pieces of wax paper and flatten with meat pounder until thin

Cut each chicken breast into 4 pieces

Add some flour in a shallow bowl. Dredge chicken in the flour and shake off excess.

Add butter and olive oil in a large pan over high heat and heat until sizzles. Do not let it brown.

Add the chicken and saute until brown on both sides. Stir in sliced mushrooms and saute briefly, then add garlic. Add Marsala and simmer for 3 minutes, then stir in flour, pour in beef stock and let simmer until sauce thickens, about 3-5 minutes.

Transfer to serving platter and serve.