How to Make It
In a small bowl, cover the prunes with the brandy and let stand for 30 minutes. Strain and coarsely chop the prunes; reserve the prune brandy.
In a skillet, melt 3 tablespoons of the butter. Add the onion and cook over moderate heat, stirring, until softened, 5 minutes. Add the goose liver and cook until no longer pink, 2 minutes. Add the port to the skillet and boil, scraping up any browned bits, until almost evaporated, 2 minutes.
Scrape the mixture into the bowl of a stand mixer fitted with the paddle; let cool slightly. Add the ground pork, eggs, allspice, thyme and garlic and season with salt and pepper. Beat the stuffing at low speed until thoroughly combined, frequently scraping down the side of the bowl. Stir in the chestnuts and prunes.
Preheat the oven to 425°. Set a rack in a roasting pan. Season the goose cavity with salt and fill with the stuffing; secure with toothpicks. Using a paring knife, prick the skin all over. Truss the goose and set it breast side up on the rack. Roast for 15 minutes, then reduce the oven temperature to 350° and roast for 3 1/2 hours, until an instant-read thermometer inserted into the stuffing registers 160° and the thigh registers 165°. Baste the breast every 15 minutes with 1/4 cup of boiling water; transfer to a board and let rest for 15 minutes.
Pour the pan juices into a measuring cup and skim off the fat. Return the juices to the pan; add the reserved prune brandy and the stock. Boil the sauce, scraping up any browned bits stuck to the bottom of the pan, until it is slightly thickened, 10 minutes. Remove from the heat and whisk in the remaining 4 tablespoons of butter. Season the sauce with salt and pepper.
Discard the toothpicks and string. Spoon the stuffing from the cavity into a serving bowl. Carve the goose and serve with the stuffing and sauce.
The goose can be ordered online at schiltzfoods.com.