To 7½ dl (1⅓ pt or 3¼ U.S. cups) fish Velouté add 1 dl (3½ fl oz or ½ U.S. cup) each of mushroom cooking liquor and cooking liquor from mussels, 2 dl (7 fl oz or ⅞ U.S. cup) Fish Stock made from sole bones, a few drops of lemon juice and a thickening of 5 egg yolks mixed with 2 dl (7 fl oz or ⅞ U.S. cup) cream. Reduce it quickly by one-third over an open fire, using a metal spatula, to give approximately 8 dl (1⅖ pt or 3½ U.S. cups) of sauce. Pass through a fine strainer and finish with 1 dl (3½ fl oz or ½ U.S. cup) double cream and 125 g (4½ oz) butter.

This sauce is special for serving with Sole Normande but also has a wide range of applications as a basis for other fish sauces.