Preheat the oven to 170C.
Soften the butter and mix with the sage, garlic, salt and pepper.
Once the butter is made, carefully stuff the crown under the skin,
distributing the butter evenly throughout, taking care not to tear the skin.
Rub the rest of the turkey with salt and pepper and place in a roasting tray.
Roast the crown for 70 minutes or until the juices run clear.
Remove from the oven and allow to rest for 20 minutes before carving.
Squeeze the sausage meat from the skins and reserve the meat in a bowl.
Try to break it up as much as possible.
Remove crusts from bread and cut into 1-2cm chunks then set aside in a large bowl.
Fry the onion, garlic and celery in half the oil until they just start to colour.
Add the sausage meat and break up as much as you can.
Gently fry the sausage meat until it is just cooked, then add the wine
and heat gently for around 2 minutes.
Combine the sausage and onion mixture with the bread along
with the chopped walnuts, parsley, and the rest of the oil and the zest of the lemon.
Give the stuffing a good mix around and season with some salt and pepper if needed.
Place stuffing mixture into a baking dish and place under a hot grill until golden brown.