Asparagus and hollandaise sauce

To make the hollandaise sauce, place the vinegar and lemon juice in a small saucepan and bring to a simmer. Cook until reduced by about three-quarters, or until about 2 tablespoons remain.

Add the reduced vinegar mixture to the egg yolks in a glass bowl, placed over a pan of simmering water, and whisk until thick and trebled in volume.

Gradually add the melted butter, whisking constantly, until all the butter has been incorporated. Season.

Place the asparagus in a pan of boiling water, return to the boil and simmer for 3 ½ to 4 minutes, or until the asparagus is just tender, drain. Serve generously drizzled with the sauce.