Photograph: Phillip Webb
Preheat the oven to 220°C, fan 200°C, gas 7. Brush the turkey all over with the 2 tablespoons of oil, then rub salt and pepper into the skin. Simply place the onion halves, a few strips of lemon rind and the herb sprigs into the bird's cavity. Set the turkey, breast down, in a large, oiled roasting tin. Protect the wings and legs with kitchen foil to prevent them from drying out. Place the turkey in the oven and roast for 30 minutes, then turn the heat down to 200°C, fan 180°C, gas 6 and continue roasting for 1¼ hours. Baste the turkey periodically with the juices in the roasting tin.
Meanwhile, for the gravy, heat the oil in a large saucepan over a medium heat, add the vegetables and fry for 30-35 minutes, stirring occasionally, especially towards the end, until really well browned (this is your gravy browning). Add the garlic a few minutes before the end. Sprinkle the flour over and stir, then gradually add the wine and Marsala and cook, stirring, for a couple of minutes to thicken. Stir in the stock in 2 or 3 goes, add some seasoning and simmer for about 5 minutes. Sieve the gravy, pressing out as much as possible from the vegetables. Set aside until needed.
To make the stuffing balls, melt the butter in a large frying pan over a medium heat, add the onion, apple and sage, and fry for 6-8 minutes until softened and glossy, without colouring. Add the chestnuts, season and cook for a minute or two longer, then leave to cool. Slit the sausages open and slip the meat into a large bowl. Add the cold chestnut mixture and combine. Take heaped tablespoons of the mixture and shape into 24 balls.
For the chipolata rolls, heat a frying pan over a medium to high heat and colour the chipolatas all over for 5-7 minutes – you will need to do this in 2 batches. Cool, then wind a rasher of pancetta along the length of each chipolata and secure with a cocktail stick. Arrange the rolls in a roasting tin, ready to pop in the oven. Blend the honey and mustard together in a small bowl and set that aside, too.
After the turkey has had its 1¼ hours cooking at 200°C, fan 180°C, gas 6, turn it over so the breast is uppermost. Return the turkey to the oven for a further 20-30 minutes until the breast is golden. After 15 minutes, add the stuffing balls and the chipolata rolls to the oven on a baking tray to cook for 20-25 minutes, brushing the chipolata rolls halfway through with the honey-mustard glaze. After the further 20 minutes' cooking time, check if the turkey is properly cooked through by inserting a skewer into the thickest part of the flesh at the thigh – the juices should run clear. If not, put the bird back into the oven for another 10 minutes, then check again. When the turkey is ready, move it to a suitable carving platter or board, cover with kitchen foil and leave to rest for at least 20 minutes.
Skim the fat off the juices in the turkey roasting tin, add the Marsala gravy to the tin and reheat together over direct heat. When simmering, whisk in the butter, which will give the gravy a lovely glossy finish. Serve the turkey with the stuffing balls, the chipolata rolls (cocktail sticks removed) and the Marsala gravy.
Get ahead: the gravy can be made up to 2 days ahead; the stuffing balls and chipolata rolls can be prepared at the same time. Keep chilled. The stuffing balls can also be frozen; defrost in the fridge overnight.
Kitchen secret: by roasting the bird upside down, the juices released during cooking baste the breast, and at the same time you are protecting the white meat from the drying ravages of the heat at the top of the oven.