Method: Heat turkey drippings in a saucepan. Add 3 1/2 cups chicken broth and bring to a boil. Stir cornstarch into remaining 1/2 cup cold chicken broth. Stir cornstarch mixture into gravy base and stir continually until it returns to a boil.Reduce heat to a simmer for about 10 minutes.Season to taste with salt and pepper.dd 3 1/2 cups chicken broth and bring to a boil. Stir cornstarch into remaining 1/2 cup cold chicken broth. Stir cornstarch mixture into gravy base and stir continually until it returns to a boil. Reduce heat to a simmer for about 10 minutes. Season to taste with salt and pepper.