Before starting this Mousseline Sauce recipe, make sure you have organised all the necessary ingredients.
Clarify the butter in a small saucepan.
The butter should melt very slowly on a hotplate or a stove.
Clarify the eggs.
Place the egg yolks in a sauté pan. Season with salt and a pinch of Espelette pepper.
Add 20ml of water per egg yolk.
Vigorously beat the eggs, using a small whisk...
... making 8-shaped movements, while cooking on slow heat.
Cooking should be done at a temperature of approximately 65°C in order to obtain a sabayon sauce. (Prefer the use of a stainless steel or copper saucepan.)
When the preparation has the consistency of a cream, take the recipient off the heat. (Every motion of the whisk should be such that you can see the bottom of the recipient.) During the cooking process, if you notice the egg yolks are too thick, you can add a little water.
When the butter has completely melted, skim the surface using a small skimmer.
Decant the clarified butter. Keep warm.
Away from the heat, gradually add the clarified and decanted butter to the sabayon sauce, and combine with a small whisk. Add the lemon juice last. Keep warm.
Beat the whipping cream until you obtain a whipped cream, using an electric whisk.
Gently add the whipped cream to the hollandaise sauce.
Combine gently with a rubber spatula. Adjust the seasoning if needed. Keep warm on low heat. Do not use bain-marie cooking, as this could cause the sauce to collase. The mousseline sauce is ready to serve! It is delicious with asparagus or fish.