In a large skillet, saute mushrooms in butter until tender. Add wine or broth. Bring to a boil. Reduce heat; simmer, uncovered, for 4 minutes. , Combine the flour, sour cream, pepper and nutmeg until smooth; stir into mushrooms. Cook and stir for 1-2 minutes or until bubbly. Transfer to a shallow serving dish. Sprinkle with cheese and parsley.