Combine the apple, chopped ginger, and peppercorns in a bowl. Stuff the mixture into the duck and close the skin using a wooden skewer (to hold in the stuffing). Hang the duck for 2 hours at room temperature (place a pan underneath it to catch the drippings). Place the duck on a pan fitted with a rack (breast side up), and roast in a preheated 375 degree convection oven for 40 minutes. If you don't have a convection oven, roast the duck in a conventional oven at 400 degrees for 55 minutes, or until the duck is a deep golden brown color. To serve, allow duck to rest 5 minutes before cutting. Carefully remove breast and leg from the duck.
POSTRIO POMEGRANATE SAUCE: In a medium sized saucepot, heat 1 tablespoon of vegetable oil. Add shallots, and sweat, do not cook until the shallots color. Add wines and bring to a boil. Add cinnamon stick, star anise, and rosemary. Reduce wine by 2/3, add chicken stock, demi-glace, and 3/4 cup of the pomegranate seeds, and reduce by half, until sauce reaches a syrupy consistency. Remove sauce from heat, season with salt and pepper, and whisk in the tablespoon of butter. Strain sauce through a fine chinois and serve or keep hot in a hot water bath. When serving sauce, garnish with the leftover 1/4 cup of pomegranate seeds.