If using a frozen bird, make sure that the turkey is completely thawed before using. Take the turkey out of the refrigerator a couple of hours before you intend to start cooking, to allow it to come to room temperature.
Put the turkey in a large roasting tin, make up the stuffing as packet instructions and use to stuff the neck of the bird. Sprinkle the turkey with the basil and paprika and season. Lay the bacon rashers over the breast, if using, and tuck the lemon and orange slices around it. Loosely cover with foil, tucking the edges in around the edge of the roasting tin. Roast in a preheated oven, 180°C (350°F), Gas Mark 4, for 20 minutes per 500 g (1 lb) plus 20 minutes. Baste regularly.
Remove the foil 20 minutes before the end so that the turkey browns. Transfer the turkey to a warm serving dish, cover with foil and leave to rest while you make the gravy. Skim off and discard the fat from the pan juices, then pour in the stock and port or wine and bring to the boil. Stir in cornflour and some cold water to thicken the gravy. Carve the turkey and eat with roast potatoes, carrots and vegetables of your choice.