Melt butter in a sauce pan and keep it aside.

Peel the shallots and chop it.

Put it in a small saucepan and add 1 tbsp of tarragon. Add the vinegar.

Bring to the boil and simmer it until you are left with a tbsp of liquid.

Let it cool for some time.

Then add the egg yolks, 2 tbsp of water, salt and pepper. Mix it well.

Heat it and leave to thicken, stir it continuously.

When thickened, convert it to a bowl and whisk.

Add the melted butter drop by drop to it until the mixture becomes creamy.

Add the rest of the chopped tarragon and whisk for 10 sec at max speed. Heat it.

Serve it with grilled meat/fish.