Using the pan you've just used to roast your turkey (or chicken), sprinkle the flour evenly over the pan juices. Using a whisk, mix the flour with the pan juices. Heat over a medium-low element until the mixture slightly bubbles. Gradually add the chicken stock and then the wine, stirring constantly. Once all stock and wine has been added, turn the heat up to medium and bring the liquid to a gentle boil.
Don't worry if there are bits or lumps at this stage.
Once the gravy is at a gentle boil, strain the gravy into a medium sized saucepan through a sieve. Cook over a medium-high heat until the gravy has thickened - about 10 to 15 minutes. Season with salt and pepper. Serve hot.