If using, insert a meat probe through the thickest part of the meat, avoiding the cavity.
Turn the chicken breast side down in the tray.
Bake for 25 minutes, then turn the chicken breast side up.
Bake for a further 25-45 minutes until the core temp reaches 85C/185F at the deepest point, the skin is crisp and golden, the inner flesh is white with no pinkness anywhere, and the juices run clear.
Spoon some of the buttery juices back over the top of the chicken, then transfer to a serving platter, cover with foil and leave to rest for 15 minutes.
I dressed my platter with pan-fried sprouts with sage, and served with roast potatoes, boiled carrots, and a gravy made from the remaining juices in the roasting pan.