French Lemon Sole with Butter Sauce

Ingredients:

60 gr of cold butter (to finish the sauce)
25 gr of butter (for the roux)
25 gr of flour (for the roux)
2 eggs yolks
70 gr of Crème Fraiche
The juice of 1/2 lemon
40 Cl (400 ml) of fish fumet/stock
Salt and pepper

Instructions:

1.Melt 25 g of butter in a saucepan, add the 25 gr of flour and mix well.
Moisten with the fish fumet and stir until it's thickens

2.Season and leave to cook gently for 1/4 of an hour.
on the side whisk 2 egg yolks with a spoonful of crème Fraiche
Then, take you veloute off the heat and pour that mix in the sauce.

3.Stir well then add the lemon juice.
Finally, Incorporate 40 to 60 gr of butter while continuing to whisk.
(note that once the eggs are in the sauce must not boil or it will split)