1. Brown turkey necks in hot oil in a large saucepan over medium-high heat 2 to 3 minutes on each side. Add onion and celery; sauté 5 minutes. Stir in broth, parsley, and thyme. Bring to a boil; reduce heat, and simmer, stirring occasionally, 30 minutes. Pour through a wire-mesh strainer; discard solids.
2. Melt butter in a large skillet over medium-low heat; whisk in flour until smooth. Cook, whisking constantly, 4 to 5 minutes or until mixture is golden. Gradually whisk in stock (or pan drippings), wine, and sage; bring to a boil over medium heat. Reduce heat; simmer, stirring occasionally, 5 to 10 minutes or until thickened. Stir in salt and pepper to taste.