Turkey Tetrazzini 1/2 lb. sliced mushrooms2 T. butter2 T. chopped fresh parsley1 lb. cooked spaghetti3 C. cooked diced turkey1/2 C. grated Parmesan cheeseCream Sauce:1/2 C. butter1/2 C. flour1 C. hot milk1 C. hot chicken stock1 t. salt1/2 t. freshly ground black...