How to Make It
In a small bowl, combine the prunes with the Armagnac. Cover and refrigerate for at least 2 hours or for up to 1 week. Drain the prunes well and reserve the liquid for another use.
Preheat the oven to 325°. Using paper towels, pat the goose completely dry on the outside and inside. In a large bowl, toss the prunes with the apples and garlic. Stuff the goose with the prune mixture and tie the legs together with twine. Generously rub the goose with oil and season all over with salt. Transfer the goose, breast side up, to a rack set in a roasting pan. Place the neck in the bottom of the roasting pan. Roast for 40 minutes, then remove the pan from the oven. Carefully tilt the pan and spoon the fat into a small heatproof bowl.
Return the goose to the oven and increase the temperature to 350°. Roast for 50 minutes. Remove the pan from the oven again. Carefully tilt the pan and spoon the fat into the bowl. Remove the goose neck and reserve for snacking, if desired.
Return the goose to the oven and increase the temperature to 400°. Roast for about 40 minutes longer, until the skin is golden brown and an instant-read thermometer inserted in the inner thigh registers 160°. Transfer the goose to a work surface, tent with foil and keep warm. Pour the boiling water into the pan and scrape up any bits on the bottom using a wooden spoon. Pour the pan juices into a heatproof bowl.
In a medium saucepan, heat 2 tablespoons of the reserved goose fat over high heat. Add the giblets and cook until browned, about 1 minute. Add the chicken stock and the reserved pan juices and bring to a boil. Reduce the heat to low and simmer for 5 minutes. Add the cream and simmer for 3 minutes. Stir in the vinegar and currant jelly and season with salt and pepper. Strain the gravy into a gravy bowl or small pitcher. Carve the goose and transfer to a platter. Spoon the prunes and apples into a serving bowl and serve with the gravy.