Hollandaise Sauce

1/Make the butter slowly melt and then take away the whey on top and keep the butter warm.
2/In a small saucepan, reduce on heat the vinegar until it remains 2 tablespoonfuls and cold it down by putting the bottom of the sauce pan into cold water. Add the yolks and 2 tablespoonfuls of cold water and stir well.
3/In a bain-marie close to the boiling point, whip continuously your sauce by drawing "8" shapes. When the sauce has become thick enough, take the sauce pan out of the heat and gently and progressively pour the melted butter and work as if you were making a mayonnaise.
4/Add 1 pinch of table salt, then the lemon juice that will dissolve the salt and gently mix it with the wheep (note of the translator : the lemon juice will make the sauce a lighter colour)