Bring the turkey to room temperature for at least one hour.
Preheat the oven to 230°C.
Brown the turkey wings and neck in rapeseed oil in a roasting tray for 10 minutes.
Smear the turkey with butter seasoned with salt and white pepper.
Place the turkey on top of the wings and roast for 30 minutes.
Baste the turkey with cooking juices and reduce oven to 160°C.
Add 200ml water and roast for 1 hour, basting every 20 minutes.
Ensure the internal temperature reaches 74°C.
Rest the turkey for at least 30 minutes in a deep-sided tray.
Boil the juices in the roasting tray while scraping the bottom.
Stir in the dissolved arrowroot to the juices to thicken the gravy.
Strain the gravy and serve with the carved turkey.