Heat the oil and butter in a saucepan and fry the onion and rosemary for 5-6 minutes. Remove from the heat and stir in the remaining stuffing ingredients until well combined. Season.
Preheat the oven to 180°C/Gas mark 4. Melt the butter in a small saucepan, stir in the saffron threads and leave to cool slightly.
Push some of the stuffing into the neck end of the bird packing it right up to the breast meat. Secure the neck skin with cocktail sticks. Roll the remaining stuffing into balls (these can be cooked separately for 30 minutes).
Weigh the turkey and calculate the cooking time at 20 minutes per kg + 90 minutes at the end. Push the lemon halves and bayleaf into the cavity and place in a roasting tin. Brush the whole bird with the saffron butter and season well.
Cover with foil and roast. Remove the foil and baste with any remaining saffron butter and roast uncovered for the last hour of cooking time. To check to see if the turkey is cooked push a metal skewer into the thickest part of the leg - if the juices run clear the turkey is cooked if the juices are slightly pink pop back into the oven for a further 15 minutes before checking again. Cover with foil and allow to rest for 20-30 minutes before carving.
© Phil Vickery
For the stuffing:
For the turkey: