1 fresh goose, 12 to 14 pounds, wing tips cut off and reserved for stock
Coarse salt and freshly ground pepper
Pork and Prune Dressing or your favorite stuffing
2 shallots, chopped
1/2 cup port or Madeira
3 cups Brown Goose Stock (recipe follows) or chicken stock
2 tablespoons cornstarch
1 tablespoon fresh lemon juice
2 tablespoons unsalted butter
Heat the oven to 275°F. Remove any loose fat from the goose. Rinse the bird inside and out with cold running water and pat dry. Season liberally inside and out with coarse salt and pepper. Prick all over, especially in the fatty parts. Stuff loosely. The bird will hold 6 to 7 cups of stuffing; bake the remainder separately as directed. Sew up the cavity and tie the legs together.
Put the goose upside down on a rack in a large roasting pan and roast for 1-1/2 hours. Remove the fat that accumulates in the bottom of the pan with a bulb baster, saving it in a heatproof container. Turn the bird right side up, prick the goose again, and baste with hot water. Continue to roast for 2 hours longer, basting with about 1 cup of hot water every 30 minutes or so to keep the fat in the roasting pan from burning and removing the accumulated fat from the roasting pan with a bulb baster as necessary to avoid smoking.
Raise the oven temperature to 400°F and roast the goose 45 to 60 minutes longer, until the skin is crisp and mahogany brown and the goose joints are loose.
Transfer the goose to a carving board and cover loosely with foil to keep warm. Pour out all but 2 tablespoons fat from the roasting pan. Add the shallots and set over moderate heat. Cook for 1 minute, or until softened. Pour in the port and bring to a boil, scraping up all the flavorful brown bits from the bottom and sides of the pan. Boil for 1 minute. Add 2-1/2 cups of the stock and return to a boil. Pour the sauce into a saucepan.
Dissolve the cornstarch in the remaining 1/2 cup stock; stir into the sauce. Bring to a boil, stirring, until thickened and smooth. Add the lemon juice and whisk in the butter. Season with salt and pepper to taste.
Brown Goose Stock
Render about 2 tablespoons goose fat in a heavy medium saucepan over moderately low heat. Add the cut-up goose neck, giblets, and wing tips and a sliced onion and carrot. Saute over moderately high heat until deeply browned. Add 6 cups water, 2 bruised garlic cloves, a bay leaf, several sprigs of parsley, 1/4 teaspoon thyme, 8 peppercorns, and 8 to 12 mushroom stems if you have them. Reduce the heat to low and simmer, skimming occasionally, for 1-1/2 to 2 hours; strain. Measure the stock and, if necessary, boil down to 3 cups.