Use the turkey giblets and neck to make a flavorful stock for this citrus-spiked gravy. Or use 4 cups store-bought chicken broth.
- To prepare stock: Combine turkey neck and giblets, water, onion, carrot and celery in a large saucepan; bring to a boil. Add bay leaf, thyme and peppercorns. Reduce heat and simmer, skimming and discarding any foam, for 1 hour. Strain stock through a fine-mesh sieve into a medium bowl and let cool. Discard solids. If necessary, add enough water (or reduced-sodium chicken broth) to measure 4 cups stock.
- To prepare gravy: Remove the turkey from the roasting pan. Skim off any visible fat from the pan juices.
- Whisk 1/2 cup of the stock and flour in a small bowl until smooth; set aside.
- Set the roasting pan over two burners on medium heat. Add wine; bring to a boil and cook, scraping up the browned bits, until the liquid is reduced by about half, 2 to 4 minutes. Add the remaining 3 1/2 cups stock. Increase heat to medium-high; return to a boil, stirring often. Boil until the liquid is reduced by about half, 6 to 8 minutes.
- Whisk the reserved flour-stock mixture and add to the pan, whisking constantly, until the gravy thickens, 1 to 3 minutes. Stir in lemon juice (or lemon and orange juices). Remove from the heat and pour the gravy through a fine sieve into a large measuring cup. (Discard the solids.) Season with salt and pepper.