For the Waldorf salad, mix the mayonnaise with the lemon or lime juice, season with sugar, salt and pepper.
Cut the flesh of the pineapple into small cubes. Peel the apples and celery. Cut the apples and celery into cubes, and the celery into strips. Cut the roasted chicken fillet into small pieces.
Mix the ingredients together and stir gently. Sprinkle the Waldorf salad with the walnuts before serving.