This is a dark, rich - almost brown - gravy. It can be made up to three days in advance; I usually make it on Tuesday. If you make it prior to your frozen turkey thawing out (which I usually do), you can usually procure turkey necks or extra turkey gizzards at the butcher's. Just substitute those for what you'd pull out of your turkey.
Last year after Thanksgiving, I made turkey stock from the turkey carcass, and froze it. I substituted that this year for the chicken stock, and I have to say so far that the taste is really worth it. But regular chicken stock will certainly do.
Reserved turkey giblets, neck and backbone, hacked into 2-inch pieces*
1 medium carrot, cut into 1-inch pieces
1 rib celery, cut into 1-inch pieces
2 small onions, chopped coarse
6 cloves garlic, unpeeled
3 1/2 cups chicken stock
2 cups dry white wine
6 sprigs fresh thyme
1/4 cup unbleached all-purpose flour
Salt and pepper
Heat oven to 450 degrees. Place turkey trimmings, carrot, celery, onions, and garlic in large roasting pan. Spray lightly with cooking spray and toss to combine. Roast, stirring every 10 minutes, until well-browned: 40-50 minutes.
Place roasting pan over burner on high; add chicken stock and bring to a boil, scraping up browned bits on bottom of pan.
Transfer contents of roasting pan to dutch oven. Add wine, 3 cups of water, and thyme; bring to a boil. Reduce heat to low and simmer until reduced by half, about 1 1/2 hours. Strain stock into another container, and cool to room temperature. Cover with plastic wrap and refrigerate until fat congeals, at least 1 hour. (Note: I usually do this on Tuesday and put it in the fridge overnight, then finish the gravy on Wednesday.)
To finish, skim fat from stock and reserve. Pour stock into another saucepan through a fine-mesh strainer and discard any solids. Bring stock to a simmer over medium-high heat. In a second saucepan, heat four tablespoons turkey fat (note: I use a little butter if I don't have enough fat) until bubbling; whisk in flour and cook, whisking constantly, until combined and honey-colored, about 2 minutes. Continuing to whisk constantly, add hot stock by the ladleful, then reduce the heat to medium low. Simmer, stirring occasionally, until slightly thickened, about 5 minutes.
Season to taste with salt and pepper and serve.
Note: Gravy can be refrigerated for up to 3 days. Reheat in a medium saucepan over medium heat until hot - about 8 minutes.
*Honestly, I don't usually bother with the hacking part. I throw the trimmings in whole and it comes out fine.