Preheat the oven to 200°C.
To make the stuffing, heat a little olive oil in a frying pan. Add the onion, garlic and crumble the chestnuts and cook over a low heat for about 5 minutes or until the onion is soft. Remove from the heat and set aside to cool.
Blanch the spinach in boiling salted water until just wilted, then drain and rinse under cold water. Squeeze the excess water from the spinach. Chop coarsely.
Combine the onion mixture with the spinach, bread crumbs, herbs, raisins and butter in a medium bowl. Add the eggs, season with salt and pepper and mix well.
Get the butcher or do it yourself, cut the back bone out of the turkey and press it flat butterflying it, remove the wish bone.
Get your fingers and then hands between the skin and flesh of the turkey and gently without breaking the skin loosen it to make pockets for the stuffing.
Press the stuffing under the skin of the turkey on the breasts and legs, until it’s firmly packed in. Rub the skin with plenty of olive oil and season the turkey inside and out.
Place the turkey in a large baking tray and roast for 30 minutes. Reduce the oven temperature to 150°C and cook the turkey for 4hours or so until cooked. (The best way to ensure the turkey is cooked through is with a meat thermometer. If the bird is larger add 20-30 minutes for every 500g over 7.6kg. When cooked, the internal temperature of the breast should be 74°C and the legs 80°C.)
Reduce the oven temperature to 50°C, cover the turkey with foil and allow it to rest in the oven for about 20 minutes.
To serve, remove the drumsticks, thighs and wings at the second joint. Slice the breasts into 1-2cm thick slices, being careful not to rip the skin. To serve place some breast and leg meat on each plate, drizzle with evo, season with salt and freshly ground pepper and give a good squeeze of lemon juice.