In heavy medium saucepan or fondue pot, over medium heat, melt cheese and margarine. With wooden spoon, stir in remaining ingredients except sherry; cook, stirring, over low heat until mixture is smooth and thick. Stir in sherry. Serve at once. Makes 4 servings. Each serving provides: 2 Pro Ex, 1 Fat Ex, 25 cal Opt Ex. Per serving: 291 cal, 15 g pro, 23 g fat, 5 g car, 451 mg sod.