Combine first 4 ingredients in the top of a double boiler. Place over boiling water; cook 1 minute or until thickened, stirring constantly. Add butter; stir until butter is melted. Cool slightly.
Beat egg yolks until thick and lemon colored. Stir egg yolks and turkey into cornmeal mixture. Beat egg whites (at room temperature) until stiff but not dry; gently fold into cornmeal mixture. Pour into a lightly greased shallow 2-quart baking dish. Bake at 350° for 1 hour or until a knife inserted in center comes out clean. Serve giblet gravy over spoon bread.