Peel the chestnuts and cut each into quarters. Gently simmer the chestnuts in the stock in a saucepan over medium heat for 10 minutes, or until tender. Crumble the sausage and brown it in a frying pan over medium heat. Transfer the sausage to a colander to drain off the fat. Melt the butter in the sausage pan. Cook the celery over low heat for 5 minutes, or until tender, adding the ham after 3 minutes. Stir in the bread cubes, cooked sausage, cooked chestnuts, half of the stock, and salt and pepper to taste. Add stock as necessary; the stuffing should be moist but not soggy. Spoon the stuffing into a buttered baking dish; cover with foil and bake in a 350F oven for 15 minutes, or until thoroughly heated. Alternatively, spoon the stuffing into the cavity of a capon or turkey. Nutrient Value per Serving: 321 Calories, 14 g Fat, 6 g Saturated Fat, 12 g Protein, 36 g Carbohydrate, 34 mg Cholesterol, 572 mg Sodium. [The Washington Post; January 9, 1991]