Eggs Benedict

Method

1. Melt 30 g of unsalted butter in a small pan over a low heat and set it aside somewhere warm — it should be liquid but not hot enough to scramble a yolk. Skim off any foam.
2. Set a heatproof bowl over a pan of barely simmering water, making sure the base does not touch the water. Whisk 1 egg yolk with 1 tsp of white wine vinegar and 1 tsp cold water for about 3 minutes, until pale, foamy and thick enough to leave a ribbon trail.
3. Take the bowl off the heat and trickle in the warm melted butter drop by drop at first, whisking constantly, then in a thin stream once the sauce thickens and emulsifies. Whisk in 1 tsp of lemon juice, a good pinch of salt and a pinch of cayenne. If it tightens too much, loosen with a teaspoon of warm water. Cover and keep in a warm place, off direct heat.