1. Heat oven to 350 degrees F.
2. If using fresh chestnuts, make large X in flat side of each chestnut with small knife. Place chestnuts on baking sheet. (Omit baking and peeling if using canned chestnuts.)
3. Bake in 350 degree F oven for 20 to 25 minutes or until shell curls back. Let cool. Peel off shell and dark membrane. Coarsely chop fresh or canned chestnuts. Place in large bowl.
4. Cook bacon and onion in large nonstick skillet over medium heat for 6 minutes. Add mushrooms; cook for 6 minutes or until mushrooms are tender. Add to chestnuts.
5. Cook sausage in same skillet, breaking up with wooden spoon, until cooked through, about 10 minutes. Remove meat with slotted spoon to chestnut mixture.
6. Add bread cubes to chestnut mixture. Mix in broth, cognac, thyme, sage, rosemary and nutmeg.
7. Spoon stuffing into 13 x 9 x 2-inch baking dish that has been coated with nonstick cooking spray. Cover dish with foil. Refrigerate until ready to use. (Or use to stuff 12- to 15-pound turkey and bake; do not stuff in advance. Roast turkey according to package directions)
8. To bake, let stand at room temperature 1 hour. Heat oven to 350 degrees F. Bake in 350 degree F oven for 45 minutes. Remove foil and bake another 25 minutes or until browned on top. Makes 10 servings.