Ingredients

　　2 pounds Jerusalem artichokes (sunchokes), peeled, sliced, and reserved in a bowl of cold water

　　6 cups sliced celery plus celery leaves for garnish

　　2 cups water

　　1 quart (4 cups) chicken broth

　　2/3 cup dry white wine

　　1 tablespoon English-style dry mustard

　　2 cups half-and-half

　　1/8 teaspoon freshly grated nutmeg

　　In a stainless steel or enameled kettle combine the Jerusalem artichokes, drained, the sliced celery, the water, the broth, the wine, and the mustard and simmer the mixture, uncovered, for 30 minutes, or until the vegetables are tender. In a blender purée the mixture in batches, transferring it as it is puréed to a bowl, pour the purée into the kettle, cleaned, and stir in the half-and-half, the nutmeg, and salt and pepper to taste. Heat the soup over moderate heat, stirring, until it barely reaches a boil, ladle it into heated bowls, and garnish each serving, with a celery leaf.