A friend of mine (who happens to be a great cook) told me to try using butter-soaked muslin cloth over the turkey breast while it cooks. It worked a treat - came out a beautiful colour and very moist indeed.
Preheat the oven to 180 degrees C. Set the turkey in a roasting tray, making sure you have removed any giblets. Place half a lemon and some chopped fresh herbs inside the cavity. Season generously with salt and pepper.
Melt the butter in a saucepan. Place the muslin cloth in the melted butter and leave to soak for a few minutes to absorb the butter. Place on top of the turkey and arrange in place so it covers all of the breast and legs.
Pour any remaining melted butter and 450 ml of chicken stock into the roasting tray.
Cook for 4 hours (or 20 minutes per 500g), basting the turkey all over every 30 minutes or so. Test it by piercing the legs and/or the thickest part of the breast with a skewer. If the juices run clear, it's time to rest the turkey. Transfer to a serving platter and cover with foil to keep warm.
To make the gravy, pour the juices from the roasting tray through a sieve then allow to settle, then skim off any fat from the top. Pour the skimmed gravy back in a small pan and keep warm until you are ready to serve.