Preheat the oven to 180°C (350°F). Roughly chop the bacon and set aside.

Peel the onions, wash the carrots and celery, and roughly chop all vegetables.

Put the vegetables, bacon, bay leaves, sage, and rosemary into a roasting tray,

Break the chicken wings open, and bash with a rolling pin to help release extra flavour. Place in the tray.

Drizzle everything with oil, season with salt + pepper, and toss. Cook for 1 hour, or until vegetables are tender.

Remove the tray from the oven and transfer to a low heat on the stove. Really grind and mash everything with a potato masher, scraping up all the goodness from the base of the tray (the longer you let it fry, the darker your gravy will be).

Add the sherry/port (opt.) now and allow to simmer for a few minutes.

Gradually stir in the flour, then pour in 2 litres of boiling water. Simmer for 30+ minutes, or until thickened and reduced, stirring occasionally.

When the gravy is the consistency you like, pour it through a coarse sieve into a large bowl, squeezing out as much liquid as you can with the back of a spoon.

Taste and season, cool to room temperature, then pour into containers or bags and pop into the fridge or freezer, ready to finish off on the day.

When your turkey is ready and resting, skim away most of the fat and pour your gravy into the tray with the rest of the turkey juices.

Bring to the boil on the stove, and scrape up all those sticky bits from the base. Have a taste, and season if necessary.