Beurre Blanc

Steps

1. 1
   Simmer the shallots with the wine and vinegar until only about 2 tablespoons of syrupy liquid remain.
2. 2
   Add the cream and bring back to a simmer. The cream is insurance — it stabilises the emulsion and makes the sauce far harder to split.
3. 3
   Drop the heat to very low. The pan should never be hot enough to boil from here on.
4. 4
   Whisk in the cold butter two or three cubes at a time, adding more only once the last has disappeared.
5. 5
   Keep the sauce moving and never let it exceed about 60°C, or the butter will break into oil.
6. 6
   Season with salt and white pepper. Strain out the shallots if you want it perfectly smooth.
7. 7
   Hold it in a warm — not hot — place and use within the hour. It cannot be reheated.