We value your privacy
Take the turkey crown out of the fridge 1 hour before cooking, and pat dry with kitchen paper. Heat the oven to 200°C, fan 180°C, gas 6. Mash the butter, chopped sage, mace, pepper and 1 tsp salt together in a bowl. Push half the flavoured butter in between the skin and the flesh and squidge into the meat. Massage the other half into the skin, then season well.
Add the onion slices to a roasting tin, lay the turkey breast-side down on top and cover with a tent of foil (so it’s not touching the skin).
Cook for 20 minutes per kg plus 70 minutes more (so 2 hours 10 minutes for 3kg turkey in total).
For the last 30 minutes of cooking, remove the foil tent, flip the bird over breast-side up and baste with the buttery juices (use a scrunched up piece of foil if you need to help balance it upright). Season the skin well. Add the garlic and 300ml of water to the tin and leave the foil off to crisp up the skin.
When it’s done, a metal skewer poked into the thickest part of the meat will come out piping hot and the juices clear, or a cook’s thermometer should read 70°C. Remove to a serving platter or carving board, cover with foil and leave to rest for at least 30 minutes before carving. Pour the resting juices into the roasting tray and make a gravy with the basting liquid.