Bearnaise sauce

For the sauce:

• Clarify the butter (to obtain ghee) in a bowl over a saucepan filled with water which will generate steam.
• Make a tarragon vinegar.
• Chop some tarragon and save for later.
• Chop the shallot in brunoise and soften with a little butter.
• Add the tarragon vinegar and thicken.
• Strain and add the egg yolks.
• Mix over heat.
• Add the clarified butter and continue to stir.
• Finish off by adding the freshly chopped tarragon.