Wipe duck with a damp cloth. With a cleaver chop duck, bones and all, in 2-inch sections.
Parboil chestnuts 15 minutes; then shell. Mince ginger root.
Heat oil in a large heavy pan. Brown duck sections quickly; drain off excess fat. Add stock, soy sauce, sherry, salt and ginger. Bring to a boil; then simmer, covered, 30 minutes.
Add chestnuts and simmer, covered, 10 minutes more. Meanwhile peel pear and slice thick, then sprinkle with sugar. Add to pan and cook, covered, until heated through, but not soft about 5 minutes.Servings: 4