Step 1Heat oil in saucepan over medium heat. Add turkey giblets and neck and brown well. Reserve liver for another use. Add onion, celery and carrot and cook until slightly brown, about 10 minutes.
Step 2Deglaze pan by adding white wine, then stock to pan over high heat and scraping up browned bits. Add rosemary, bring to boil and simmer uncovered until stock reduces by half.
Step 3Once reduced, discard neck and giblets. Puree stock and cooked vegetables in food processor or blender. Return to saucepan and simmer about 10 minutes.
Step 4Thoroughly mix cornstarch with water to make slurry and slowly whisk into stock, stirring constantly, until gravy reaches desired thickness. You will probably use only small portion of slurry. Keep gravy hot until ready to be served. Season to taste with salt and pepper.