1. Pour the pan juices from your roast turkey into a cup, discarding the neck and giblets. Spoon the fat from the surface of the juices and place the fat in a small saucepan.
2. Place the roasting pan across two burners of the stove over medium-high heat.
3. Add the vermouth, the reserved juices and the remaining chicken stock to the roasting pan, and scrape the browned bits from the bottom.
4. Add the bay leaves and cook for about 5 minutes.
5. Meanwhile, heat the fat in the saucepan and whisk in the flour. Cook for about 3 minutes or until the mixture is pale golden brown. Add the liquid from the roasting pan to the saucepan with the flour mixture, whisking all the time.
6. Allow the gravy to reduce until it coats the back of a spoon. Season with salt, pepper and parsley. Discard the bay leaf.