Béarnaise sauce

Method

1. Step 1

   Place the vinegar, tarragon, shallot and bay leaf and 1 tbs water in a small frying pan. Season with freshly ground black pepper. Place over high heat and bring to the boil. Cook until liquid reduces by half. Strain through a fine sieve into a heatproof bowl. Cool completely.

2. Step 2

   Use a balloon whisk to whisk the vinegar mixture and egg yolks in a heatproof bowl until pale and creamy.

3. Step 3

   Place the bowl over a saucepan of simmering water (don’t let the bowl touch the water). Continue whisking until the mixture thickens slightly. Whisking constantly, gradually add the butter, in a thin, steady stream. Whisk until well combined and the sauce thickens slightly. Remove from heat. Stir in the lemon juice, dill and extra tarragon and season with pepper to taste.