Rub saucepan with garlic; discard garlic. Melt butter, stir in flour. Slowly add broth, stirring constantly. Add parsley, cook until thickened and set aside. Saute mushrooms and onion in butter until tender. Add whiskey and thickened broth. Simmer several minutes over low heat. Serve over grilled or broiled chicken. Makes 2 1/2 cups.