There are many who prefer braised goose to roast goose because the meat is more tender and more flavorful, and the closed, moist cooking of a braise renders out more fat than open-pan roasting. A good combination to go with this would be more chestnuts, either braised or pureéd, and braised lettuce, onions or leeks. Brussels sprouts, or braised green or red cabbage are other choices. Serve a red Burgundy, Côtes du Rhône, Châteauneuf-du-Pape, or chilled Alsatian Traminer.
If using fresh chestnuts, peel them, and simmer them in stock and seasonings as described. Drain, and allow them to cool.
Prepare the stuffing and beat the sautéed liver into it. Sauté a spoonful to check seasoning.
Preheat oven to 450 degrees.
Season the cavity of the goose with salt. Starting with the meat stuffing, loosely pack alternate layers of stuffing and of chestnuts into the goose, leaving a good inch of unfilled space at the vent. Sew or skewer the vent, truss the goose, and prick its skin. Dry it thoroughly, and set it breast up in the roasting pan.
Brown the goose lightly in the hot oven for 15 to 20 minutes, turning it several times so it will color evenly.
Salt the goose and place it breast up in the roaster. Turn oven down to 325 degrees.
Brown the goose bits and vegetables in hot fat in the skillet.
Stir the flour into the skillet and brown slowly for several minutes.
Off heat, blend in the boiling stock or bouillon, and then the wine. Simmer for a moment. Then pour the contents of the skillet into the roaster around the goose. Add additional stock if necessary, so liquid reaches about one third the way up the goose.
Bring to the simmer on top of the stove. Cover, and set in the middle level of the preheated 325-degree oven.
Braise for about 2 hours and 20 to 30 minutes, regulating oven heat so liquid simmers very quietly. Basting is not necessary. Accumulated fat may be removed occasionally with the bulb baster. The goose is done when its drumsticks move slightly in their sockets, and, when their fleshiest part is pricked, the juices run pale yellow.
Remove the goose to a serving platter and discard trussing strings.
Skim the fat out of the roaster (degreasing directions), boil the cooking liquid down rapidly until it has thickened enough to coat a spoon lightly. Correct seasoning. Stir in the port and simmer a minute or two to evaporate its alcohol. Strain the sauce into a bowl or a saucepan, pressing juice out of the ingredients. You should have about 5 to 6 cups of sauce. Pour a spoonful over the goose, and serve.
(*) AHEAD-OF-TIME NOTE
For a 30- to 40-minute wait, return the goose to the roaster, and set the cover askew. Place in turned-off hot oven with its door ajar, or over barely simmering water.