This sauce is prepared by thickening Sauce Bordelaise without the marrow, with a purée of raw duck livers (not foie gras, just plain livers). Purée
For a different, and perhaps more authentic, version of Sauce Rouennaise that is thickened with blood and liver, see Sauce Rouennaise I.
Copyright © 2017 by James Peterson. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.