Drop the walnuts into boiling water, boil for 3 minutes and drain. Spread in shallow pan, dot with butter and sprinkle with garlic salt. Toast at 350ºF. for 10 minutes or until crisp, stirring occasionally, cool. Marinate walnuts, shrimp, celery and fruit in dressing for 30 minutes. Arrange in cocktail glasses and sprinkle lightly with additional garlic salt if desired. Garnish with watercress. Yield 4 -6 servings