In jar with tight-fitting lid combine first seven ingredients. Cover; shake until thoroughly combined. cut potatoes into l-inch pieces; arrange in shallow dish. Pour 1/? cup of the dressing over the potatoes, stirring gently to coat well. Set aside 30 minutes or until potatoes have absorbed most of the dressing. In 10-ounce microwave safe custard cup place walnuts and butter. Cook on High 1 to 2 minutes or until lightly toasted, stirring once. To serve; line platter with lettuce. Arrange potatoes on lettuce . Toss remaining dressing with ham and cheese. Spoon over potatoes; sprinkle with walnuts. Makes 4 servings. From the files of Al Rice, North Pole Alaska. Feb 1994