Preparation Melt butter in a 3-quart heavy saucepan over low heat, then stir in celery, carrot, and onion. Cover surface of vegetables with a buttered round of wax paper or parchment (buttered side down) and cover pan with lid, then sweat vegetables 15 minutes (to soften). Wrap parsley, cloves, and bay leaf in cheesecloth and tie into a bundle with string to make a bouquet garni. Discard buttered paper from vegetables, then add broth and bouquet garni and bring to a boil. Reduce heat and simmer, covered, 20 minutes. Add chestnuts and Madeira and simmer, covered, 3 minutes. Purée soup in small batches (4 or 5) in a blender until smooth (use caution when blending hot liquids), transferring to a 3- to 4-quart heavy saucepan. Stir in cream, pepper, and salt to taste and reheat soup over moderate heat, stirring occasionally. Cooks' note:Soup can be made 2 days ahead and cooled, uncovered, then chilled, covered.
Preparation Melt butter in a 3-quart heavy saucepan over low heat, then stir in celery, carrot, and onion. Cover surface of vegetables with a buttered round of wax paper or parchment (buttered side down) and cover pan with lid, then sweat vegetables 15 minutes (to soften). Wrap parsley, cloves, and bay leaf in cheesecloth and tie into a bundle with string to make a bouquet garni. Discard buttered paper from vegetables, then add broth and bouquet garni and bring to a boil. Reduce heat and simmer, covered, 20 minutes. Add chestnuts and Madeira and simmer, covered, 3 minutes. Purée soup in small batches (4 or 5) in a blender until smooth (use caution when blending hot liquids), transferring to a 3- to 4-quart heavy saucepan. Stir in cream, pepper, and salt to taste and reheat soup over moderate heat, stirring occasionally. Cooks' note:Soup can be made 2 days ahead and cooled, uncovered, then chilled, covered.