Zure Eiersaus

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

Ingredients

 * 4½ dl water or fish stock or beef stock
 * juice of ½ lemon
 * 30 g butter
 * 30 g flour
 * 1 egg
 * pinch of salt

Directions

 * 1) Melt the butter in a clean, smooth pan.
 * 2) Add the flour and mix the flour and butter to a white mass.
 * 3) Then add the boiling water or fish stock in small amounts, stirring well and in between bringing the sauce back to the boil.
 * 4) Then leave to boil for 10 minutes and season with salt.
 * 5) Take the sauce off the heat add part of the warm sauce to the beaten egg in small amounts.
 * 6) Once well beaten, add this back to the rest of the sauce and then whilst beating add the lemon juice in.