- Once you've transferred the cooked turkey to a platter to rest, drain off most of the fat from the roasting tray and place on the hob.
- Roughly chop the bacon, add to the tray and fry for a few minutes. Chop the onions and lemon and add to the tray with 2 rosemary sprigs and the tomatoes. Cook for 1–2 minutes, then add the turkey wings, parson's nose and drumstick tips and fry for a few more minutes.
- Pour in the cider and boil for a few minutes. Add the juices from the resting turkey and simmer to reduce the liquid by half. Pour in the stock, return to the boil, then reduce the heat slightly. Using a potato masher, crush the vegetables in the tray. Simmer for 15–20 minutes, stirring occasionally, until reduced again by a third. Take off the heat.
- Strain the gravy through a sieve into a saucepan, pressing down on the solids in the sieve with a ladle to extract as much of the flavourful juice as possible. Add a fresh sprig of rosemary to the pan, then turn off the heat and leave to infuse for a few minutes.
- Before serving, remove the rosemary and reheat the gravy. Coarsely crush the walnut pieces using a pestle and mortar and then tip into a warmed gravy jug. Pour the piping hot gravy on top and serve at once.