Ingredients
4 tablespoons tarragon vinegar (you can use wine vinegar and add extra chopped tarragon)
4 tablespoons dry white wine
2 teaspoons finely chopped shallots
pinch of freshly ground pepper
1 tablespoons water
2 egg yolks
110-175g butter, salted or unsalted
1 tablespoon freshly chopped tarragon

Serves 8 -10

Method

1. Boil the first four ingredients together until there is only about a teaspoon of liquid left in the pan, do not allow to brown.
2. Add 1 tablespoon of water immediately. Remove from the heat and allow to cool for 1 or 2 minutes. Whisk in the egg yolks and add the butter bit by bit over a very low heat, whisking all the time. If it starts to scramble remove from the heat and add a little cold water. Finally add 1 tablespoon of tarragon and taste for seasoning.