Preparation
Place a medium-sized sauce pan over medium heat with the butter. Once the butter has melted, add the flour to make a roux. Cook, stirring constantly, for about 2-3 minutes, until lightly golden in color.
While roux is cooking, place the roasting pan that you cooked your turkey in on a burner over medium-high heat. Once the pan gets hot, add the wine and scrape up all the bits on the bottom of the pan with a wooden spoon. Add the bits to the roux along with the stock and season with salt and freshly ground black pepper.
When ready to serve, beat an egg yolk in a small bowl with a ladle of the sauce.
Pour the egg yolk mixture back into the pot of sauce. It will make a glossy, more stable gravy.