A successful turkey gravy comes out of technique more than ingredients. Producing gravy at the consistency you prefer -- and free of lumps -- takes a bit of practice. But once you master the technique, your gravy will be smooth and creamy every time.
After you take the turkey out of the roasting pan, set the pan so it spans two burners on your stove. Use a whisk or a spoon to scrape up the bits of turkey and herbs stuck to the bottom of the pan. If the turkey didn't render enough liquid, add just enough water to cover the bottom of the pan. Over low heat, bring the liquid and turkey bits to a simmer.
Whisk a couple of tablespoons of all-purpose flour into cold water in a measuring cup or small bowl until it's smooth. The more flour you add, the thicker the gravy, so aim for a thin slurry. With the liquid in the roasting pan at a simmer, add the slurry in a slow drizzle, whisking constantly until the gravy reaches your preferred consistency; take the pan off the heat. Thin the gravy if necessary with chicken stock or plain water, and season it to taste with salt and pepper.