Dutch Sauce for Fish.
Slice a little horseradish, and put it into a quarter of a pint of water, with five or six anchovies, half a handful of white peppercorns, a small onion, half a bay-leaf, and a very little lemon peel, cut as thin as possible. Let it boil a quarter of an hour; then strain and thicken with flour and butter and the yolk of an egg. Add a little elder vinegar, and then squeeze it through a tamis. It must not boil after being strained, or it will curdle.