4 tablespoons butter
1/2 cup flour
1/2 cup cognac
4 c. good chicken or turkey stock
finely chopped giblets (optional)
salt and freshly ground pepper (optional)
Melt butter in small saucepan. Add flour all at once, whisking until the flour is completely incorporated into the butter. Cook for about three minutes (this will take the raw flour taste out of the roux without giving it too much color - you want a pale blond roux). Transfer to a glass measuring cup, cool to room temperature, then cover and refrigerate.
When turkey is done, remove from pan and tent with foil. While the turkey rests, pour out all pan drippings, leaving only the brown crusty bits (fond) on the bottom.
Deglaze the roasting pan with the cognac (be sure to scrape up all of those crusty brown bits!)and allow to reduce by about three quarters (pan should be nearly dry). Add stock and bring to a simmer (if you're making giblet gravy, add those in now!)
Place the cold roux in a large saucepan. Slowly add the hot stock mixture to the cold roux, whisking constantly, and simmer until the gravy reaches the desired thickness. If you want a richer gravy, whisk in a couple of tablespoons of heavy cream). Taste and adjust seasoning if necessary before serving.