Melt 2 tablespoons butter over low heat. Add the flour and stir until well blended. Cook one minute. Slowly add milk and cook, stirring constantly, until boiling. Let sauce cool; add chopped turkey, egg yolk, salt and celery salt. Form into twelve small cones. Mix bread crumbs with ground sage. Beat egg in water. Roll cones in crumbs. Dip each cone in egg and roll again in crumbs. Place on greased baking pan and drizzle with melted butter. Bake at 350 degrees for 40 minutes.