For this take on turkey, cut the bird into pieces (which helps ensure even cooking), salt overnight, and cook slowly for juicy, tender meat. If breaking down the turkey seems to advanced, have your butcher do it for you.
Place breast halves and leg quarters in a large bowl; sprinkle with salt. Cover and chill 8 hours or overnight.
Combine reserved giblets, wings and backbone in a large Dutch oven. Add 10 cups water, 8 celery pieces, 4 onion quarters, and 4 carrot pieces. Bring to a boil over medium-high heat. Reduce heat and simmer 5 hours or until mixture measures 8 cups. Cool to room temperature. Cover and chill stock 8 hours or overnight.
Skim solidified fat from surface of stock; discard fat. Return stock to high heat; bring to a boil. Boil for 30 minutes or until stock measures 3 cups. Strain mixture througha sieve, reserving stock. Discard the solids.
Remove turkey from refrigerator, and let stand at room temperature for 30 minutes.
Preheat oven to 325 degrees F.
Arrange turkey pieces skin side up, in a roasting pan, and arrange remaining 8 celery pieces, 4 onion quarters, and 4 carrot pieces in pan. Brush turkey skin with 2 tablespoons cream; sprinkle with black pepper. Bake at 325 degrees F for 1 1/2 hours or until a thermometer inserted in the thickest part of breast registers 165 degrees F, basting every 30 minutes with 2 1/2 tablesppons stock. Remove from oven. Place breast halves and leg quarters on a jelly-roll pan or cutting board. Let stand, covered, for 30 minutes. Discard skin.
Add 1 cup stock to bottom of roasting pan; carefully scrape browned bits from bottom of pan. Place a zip-top plastic bag inside a 2-cup glass measure. Pour drippings into bag; let stand 10 minutes (fat will rise to top). Seal bag, and carefully snip off 1 bottom corner of bag. Strain drippings through a sieve into a medium saucepan, stopping before the fat layer reaches the opening; discard fat and solids. Add remaining 1 1/2 cups stock to pan; bring to a boil over medium-high heat. Combine remaining 6 tablespoons cream and cornstarch, stirring with a whisk until smooth. Stir until sauce thickens.