Sauce: Add the onions to the saute pan. Stir with spatula. After 2 minutes add the mushrooms. Saute the mixture until the onions are translucent. Deglaze the saute pan with the marsala wine. Bring wine to a simmer and add heavy cream. Simmer on low heat until reduced by half.
8 Place cooked chicken on plate and top with onions, mushrooms and sauce.