Place the crushed peppercorns, vinegar, wine, eschalots, tarragon and chervil in a small pan. Bring the mixture to a boil over high heat. Boil, uncovered, for 5 minutes or until the liquid reduces by about half (you will need about 2 tablespoons).

Strain the eschalot mixture through a fine sieve into a small bowl, pressing with a spoon to extract as much liquid as possible. Discard the eschalots, herbs and peppercorns.

Place the egg yolks and 2 tablespoons of the strained liquid in a heatproof bowl.

Use a balloon whisk to whisk the egg yolk mixture until combined. Place the heatproof bowl over a saucepan of barely simmering water and cook the sauce in a double boiler. Whisk constantly for 5-7 minutes or until a ribbon trail forms and holds its shape for about 15 seconds when the whisk is lifted. The bowl should be warm, but not too hot to handle. If you think it is overheating, lift it out of the pan until it cools slightly, then return the bowl to the pan.

Add the butter to the sauce a cube at a time, whisking constantly and adding each cube only when the one before melts and is thoroughly combined (this process should take up to 10 minutes). The sauce will lose some volume, but should still have a thick, aerated texture.

When all the butter is added, remove the bowl from the pan and stir in the extra tarragon and the passion fruit pulp.

Season with pepper and salt to taste. Serve immediately.