Bring 6 quarts of water to a boil and add 2 tablespoons salt.
Slit the chestnuts on the side with a paring knife and boil for 3 to 4 minutes in the water. Remove with a slotted spoon and, once they are cool enough to handle, but still warm, peel them.
In a large, heavy soup pot, melt 2 tablespoons of the butter and saute the speck with the onions. Add the chestnuts, fennel seeds, bay leaf, 1 quart stock, and 1 cup wine, season with remaining salt and black pepper, and bring to a simmer. Cook, loosely covered, for 1 to 1 1/2 hours, until the chestnuts are very soft but still intact.
Remove the soup from the heat and allow to cool. Remove and discard the bay leaf, then puree the soup in batches and return to the soup pot. Add the remaining stock and wine to thin the soup. Bring to a simmer, then stir in the rice and mascarpone, and simmer for an additional 2 minutes.
Meanwhile, brown the remaining 2 tablespoons butter in a saute pan, and crisp the bread in the pan.
Divide the soup evenly among 4 warmed soup bowls and top with the browned bread.
In a large, heavy-bottomed saucepan, heat the oil over high heat until smoking. Add all the chicken parts and brown all over, stirring to avoid burning. Remove the chicken and reserve. Add the carrots, onions, and celery to the pot and cook until soft and browned. Return the chicken to the pot and add 6 quarts of water, the tomato paste, peppercorns, and parsley. Stir with a wooden spoon to dislodge the browned chicken and vegetables bits from the bottom of the pan. Bring almost to a boil, then reduce heat and cook at a low simmer until reduced by half, about 2 hours, occasionally skimming excess fat. Remove from heat, strain, and press on the solids with the bottom of a ladle to extract out all liquids. Stir the stock to facilitate cooling and set aside. Refrigerate stock in small containers for up to a week or freeze for up to a month.
Recipe copyright 2001, Mario Batali. All Rights Reserved.