Dutch Sauce For Fish
====================

Ingredients
-----------
1/2 teaspoonful of flour, 2 oz. of butter, 4 tablespoonfuls of vinegar, the yolks of 2 eggs, the juice of 1/2 lemon; salt to taste.

Method
------
Put all the ingredients, except the lemon-juice, into a stew-pan; set it over the fire, and keep continually stirring. When it is sufficiently thick, take it off, as it should not boil. If, however, it happens to curdle, strain the sauce through a tammy, add the lemon-juice, and serve. Tarragon vinegar may be used instead of plain, and, by many, is considered far preferable.

Source: Mrs Beeton's Book of Household Management (1861)
Ingredify — https://ingredify.com