Start with turkey drippings to get the most flavorful gravy for your holiday menu.To make gravy using the drippings from the turkey, first you’ll need to de-fat those drippings. Place a large zip-top plastic bag in a bowl, fold back the opening of the bag, and pour the drippings into the bag.  Once the fat rises to the top of the bag—you can tell when you see a layer of fat forming at the top of the liquid—snip a small hole in the bottom corner of the bag, and drain the defatted liquid into a measuring cup, stopping before the fat layer reaches the opening.  Discard the bag with the fat. Pour the defatted drippings into a saucepan and add flour and additional broth, if needed.  Stir in the flour with a whisk, and cook over medium heat until the mixture is thickened, stirring constantly with the whisk.  Once the gravy has thickened, you can season to taste before serving.