Cut the red stems off the chard leaves. Finely chop the stems, mix them in a small bowl with the vinegar and marinate for 2 hours. Reserve the leaves separately. To make a turkey stock for the gravy: Heat the oil in a large skillet on low heat and fry the chopped onion until soft - about 10 minutes. Add the turkey wings, neck, gizzard and heart and the apple and orange juice, bring to a boil, reduce the heat and simmer, uncovered for 1 hour. This should yield 2 cups stock. Strain and set aside. Pre heat the oven to 165C. Rinse the turkey and its cavity thoroughly. Dust the top of the bird with flour. Stuff the cavity with the clove studded onion, orange and fresh herbs. Tuck the drumsticks back into the metal clip (often provided with the bird), or tie the legs with string. Put on a rack in a roasting pan, add the water, and roast for 2 1/2 hours, or until the internal temperature of the thigh is 77C. Check every half hour, and if the pan is dry, add another 1/2 cup of water. Remove from the oven and let stand about 20 minutes before carving. After the turkey has been cooking for 1 1/2 hours, place the sweet potatoes in the oven with the turkey and bake for 40 minutes. Remove and peel off the skin. Mash them in a small bowl and keep warm until ready to serve, or simply cut in half. Pour the chopped chard stalks and vinegar marinade into a small pan. Over low heat, stir in the cranberry jelly until completely incorporated and just heat through - about 5 minutes. Dont cook the jelly until it becomes syrupy. Remove from the heat and transfer to a small serving bowl. To complete the gravy: Put the roasting tin full of turkey cooking juices on a stovetop burner on medium heat. Pour in the turkey/apple/orange stock, scraping the pan until you have stirred in all the flavour filled pan residue. Strain in a fat separator cup, allowing the fat to rise to the top ~ about 5 minutes. Pour the separated turkey juice from the strainer cup into a medium saucepan, making sure not to include any of the separated fat, and heat through to the boil. Remove from the heat, stir in the arrowroot slurry, return to the heat and stir thickened over low heat - about 30 seconds. Remove from the heat and set aside. Place the reserved chard leaves in a steamer, cover, and cook for 4 minutes. Remove from the heat and set aside. To serve: Carve the turkey into thin slices, put 3 on each dinner plate and ladle with the gravy. Spoon a mound of sweet potatoes and chard on the side and garnish with the Swiss chard relish.