Salpicao de Frango Brazilian Chicken Salad

Name: Salpicao de Frango (Brazilian Chicken Salad)
Ingredients: 1 pound coarsely shredded cooked chicken; 1 (8 ounce) can whole kernel corn, drained; 1 cup pitted green olives, chopped; 0.75 cup golden raisins; 2 carrots, grated; 1 stalk celery, finely chopped; 0.25 green apple, finely chopped; 4 tablespoons heavy cream; 1 tablespoon Dijon mustard; 1 pinch white sugar; salt and freshly ground black pepper to taste; 2 tablespoons chopped fresh parsley, or to taste; 2 large lettuce leaves; 4 sprigs watercress; 2 cups shoestring potato sticks