Set the oven to moderately hot, Gas Mark 4 or 180°C/350°F.
To make the stuffing: Melt the butter in a deep frying pan and add the sunflower oil. When hot, add the bacon to the pan and cook, stirring occasionally, until the bacon starts to crisp. Add the chopped leek to the pan and cook over a medium heat for 4-5 minutes, until the leek has softened. Remove the pan from the heat.
In a bowl, mix together the breadcrumbs, herbs and seasoning. Add the bacon and leek mixture and mix well. Leave the mixture to cool slightly, then mix in the goat’s cheese and egg.
Press the stuffing into the neck cavity of the turkey. Pull the skin over the stuffing and, if necessary, use a skewer to hold it in place, or just fold the skin under the bird. Weigh the stuffed turkey to calculate the roasting time, then place in roasting tin. To calculate the cooking time, allow 20 minutes per 500g – so 5kg turkey (stuffed weight) will need 3 hours 20 minutes.
Brush the turkey skin with the melted butter. Pour 1 litre (1 ¾ pint) water into the roasting tin around the turkey. Cover the turkey in foil and place towards the bottom of the oven – with the oven shelf in its lowest position. Keep the turkey covered in foil, until the last 45 minutes of cooking time, then remove the foil, baste the turkey and return to the oven until cooked through. To check that the turkey is cooked, pierce the thickest part with a skewer. If the juices run clear, then it is cooked, but if the juices are at all pink, continue cooking turkey until they run clear. If any parts of the turkey start to brown too quickly, cover them with foil.
When the turkey is cooked, remove from the oven and transfer to a warm serving plate. Cover with a clean sheet of foil and leave to rest in a warm place foe 20-30 minutes – this will make carving the meat easier.
To make the gravy: Pour the juices from the pan into a fat-separating jug and pour off the stock. Make the stock up to 450ml (3/4 pint) with water if necessary. Pour measured stock into a pan and bring to the boil.
Meanwhile mix the cornflour with 3 tablespoons cold water. Gradually add the slaked cornflour to the boiling juices in the pan, stirring well to give a smooth gravy. Add the cornflour until the desired consistency is reached. Season to taste and keep hot until ready to serve.
For the Stuffing:
For the gravy: