Step 1

Place the dried tarragon, eschallots, peppercorns, vinegar and wine in a saucepan.

Step 2

Bring to the boil, reduce heat to medium and cook for 5 minutes until the mixture is syrupy. Strain (discarding the solids) into a heatproof bowl and set aside to cool.

Step 3

Whisk together the egg yolks and 1 tablespoon iced water until combined. Add some water to a saucepan over very low heat and place the bowl with the vinegar mixture on top, making sure it doesn't touch the water. Add the egg mixture and beat until fluffy and doubled in volume.

Step 4

Strain through a fine sieve, then return the bowl to the top of the saucepan over very low heat (again with a small amount of water in the bottom of the pan).

Step 5

Gradually add the butter making sure each piece has melted before adding the next. When the mixture starts to thicken, add 2-3 pieces of butter at a time.

Step 6

Remove from the heat. Season with salt and pepper and stir in the lemon juice and cayenne pepper. Fold in the chopped fresh tarragon.