Zure Eiersaus

Description
This sour egg sauce goes well with calf's tongue or fine fishes as tarbut, Cod and eel.

Ingredients

 * 4 1/2 dl water or fish stock or beef stock
 * juice of 1/2 lemon
 * 30gr butter
 * 30gr flour
 * 1 egg
 * pinch of salt

Directions
Make this sauce the same way as the Botersaus (fijne versie), but once off the heat add part of the warm sauce to the beaten egg in small amounts. Once well beaten, add this back to the rest of the sauce and then whilst beating add the lemon juice in.