Meanwhile, heat oil in 10-inch skillet over medium heat. Cook onion, tarragon and parsley in oil about 5 minutes, stirring frequently, until onion is tender. Stir in wine. Cook uncovered about 4 minutes or until wine has evaporated. Stir in whipping cream and mustard. Heat to boiling; reduce heat. Simmer uncovered 5 to 10 minutes or until sauce is slightly thickened.