Bring the bird up to room temperature and heat oven to 180°C/160°C Fan/Gas Mark 4.
Smear softened butter under the turkey skin and over the legs. Season well.
Weigh the turkey after it has been stuffed for accuracy, and calculate the cooking time. You should roast your turkey for 40 mins per kilo for the first 4 kilos, then 45 mins for every kilo over that weight, or until the internal temperature reaches 65-70°C.
Put in a roasting tin (breast side up) and cover the turkey and tin loosely with foil, sealing it well under the rim of the tin. Put in the oven for for the calculated cooking time, removing the foil 30 minutes before the end so that the skin can brown.
Once cooked, remove from the oven and cover with foil again, leaving the turkey to sit for 30-40 mins to allow the juices to settle through the meat.
Before serving your turkey, check that the meat is steaming hot throughout, there is no pink meat visible and when you cut into the thickest part of the meat, the juices run clear.