A richer recipe suggests the addition, off the fire, of a coffee-
cupful of Béchamel with the yolks of the eggs, and then to let
the sauce remain on the fire, en bain-marie, stirring well until
it is very hot (but not boiling) and serving it in a hot sauce-
boat. For Béchamel those who like it may read cream.
The cold form of this sauce is much easier. It will be found
most delicious with cold roast beef or any cold meat. You
simply rasp the horseradish root till you have a coffee-cupful
of fine raspings, and mingle them with a breakfast-cupful of
-ordinary mayonnaise, or tartare sauce—in summer, iced. Cream
is, of course, preferred by many : when available it may be
used instead of the oil, but the usual mixture of eggs, oil,
mustard, and vinegar, will give you a good result. Serve this
as cold as you can. Worked rather thickly this is excellent
with grilled salmon, trout, or mackerel.