POTATO, BACON, AND GRUYèRE SOUP

Steps:

• In a heavy kettle (at least 5 quarts) cook bacon over moderate heat, stirring, until crisp and spoon off all but 1 tablespoon fat. Add onions and sauté over moderately high heat, stirring, until pale golden. Add broth and 3 cups of water and bring to a boil.
• Peel potatoes and cut into 3/4-inch cubes. Add potatoes to soup and simmer, covered, 10 minutes.
• In a small bowl whisk together flour and remaining 1/4 cup water until smooth and add to simmering soup, whisking. Simmer soup, covered, 5 minutes.
• In a blender purée Gruyère with 3 cups hot soup broth. Stir purée into soup with Madeira, Worcestershire sauce, and salt and pepper to taste and remove soup from heat. Soup may be prepared up to this point 3 days ahead (cool uncovered before chilling covered). Reheat over low heat but do not let boil.
• Just before serving, stir in parsley.