Make the stuffing: In a food processor blend the pork and fat. With the motor running, add the eggs, 1 at a time, and combine well. With the motor still running, add the heavy cream in a stream. Transfer the mixture to a large bowl and add the remaining ingredients. Chill, covered, for at least 30 minutes.
Turkey Breast Preparation: With a sharp boning knife, remove the turkey breast halves beginning at the breast bone and cutting along the ribcage, using long, swift strokes, pulling the meat away from the bone as you go. Remove and reserve the fillets (tenderloins) from the underside of the breast. Remove and discard any tendons, sinew, or silverskin. Reserve
On a double thickness of cheesecloth, arrange the turkey breast skin side down with a long side facing you. Sprinkle it with half the thyme and salt and pepper, to taste. Smooth 1/4 (about 1 cup) the stuffing over the turkey breast, leaving a 1-inch border. Cover the stuffing with a layer of the ham. Cover the ham with another cup of stuffing. Halve one of the fillets and wrap each half with a piece of ham. Lay the wrapped fillets side by side, with the ends touching, on top of the stuffing.
Beginning with the long side of the breast nearest you, roll it carefully away from you into a cylinder. Fold the cheesecloth over to enclose it and twist the ends, maintaining the cylinder shape. Tie the ends securely with string. Repeat with the remaining breast.
Preheat the oven to 350 degrees F.
Pat the turkey rolls (ballontines) dry.
In a roasting pan, heat the butter and oil over moderate heat until hot and in it brown the turkey, in the cheesecloth, about 2 minutes per side. Add 6 cups stock and bouquet garni to roasting pan,
Braise the turkey, covered tightly with foil, in the middle of the oven, basting occasionally for 1 1/2 hours, or until the internal temperature is 165 degrees F and its juices run clear when the breast is pricked with a skewer.
The turkey can be made 1 day ahead up to this point and kept refrigerated, covered, in the cooking liquid. To reheat, bring to a boil over moderately high heat, baste, and heat, covered, in a preheated 350 degree F. oven, basting frequently, for 1 hour.
Transfer the turkey to a rack to cool. Unwrap it. Skim the braising liquid and strain it into a saucepan. In a small bowl, combine the arrowroot, Madeira, and cream.
Bring the strained liquid to a boil and stir in the arrowroot mixture. Cook the mixture over moderately high heat until it is thickened slightly. Keep the sauce warm, covered with a buttered round of waxed paper.
Transfer the turkey to a carving board and slice half of it into 1/2-inch slices. Transfer the slices and remaining turkey to a platter and serve warm with the sauce.
Wine Suggestions: Merlot, Hahn Estates;
Recipe courtesy of Gourmet Magazine