The vin jaune used in this sauce is a wine from the Jura region of France. It is made from grapes that have not ripened fully. The grapes are dried on straw mats before the juice is pressed from them. The resulting wine has a flavor that is a bit like a cross between a great sherry and an awful chardonnay. The vin jaune gives the sauce a distinctive, underlying taste that is hard to duplicate with other wines. The Noilly Prat is a brand of French vermouth that has a flavor distinct from the vermouths of Italy. This sauce can be used for chicken, turkey, vegetables, or other foods that benefit from a smooth, very rich sauce.