100 ml white wine vinegar
1 shallot, chopped
3 tbsp of tarragon, chopped
2 egg yolks, beaten
120 g warm melted butter
Salt and pepper
1 tsp lemon juice
- Put the vinegar, shallot, 2 tablespoons of tarragon (keep one for later) and a little salt in a saucepan and boil until reduced by half.
- Strain into a large bowl and set aside to cool.
- Add a teaspoon of water to the beaten egg yolks and add the eggs to the cooled vinegar with the lemon juice.
- Set the bowl over a pan of barely simmering water (the water shouldn’t touch the bottom of the bowl) and whisk until the egg yolks have thickened enough to coat the back of a spoon.
- Carefully remove the bowl from the heat and slowly pour in the warm melted butter, whisking vigorously as you go. You can use an electric whisk to do this.
- Once all the butter is added and you have a thick and smooth consistency, stir in the remaining tarragon, season to taste and serve.