For no good reason this has become a ‘restaurant sauce’ and has taken on mythical degrees of difficulty in the popular culinary imagination. It is conceptually a difficult construction only because we doubt that it can work: a small reduction of shallots, wine vinegar and white wine into which a lot of unsalted butter is whisked to produce a creamy emulsion. People get nervous... where is the egg yolk or the flour, they wonder? In reality, 225g / 8oz of butter is a fairly restrained volume to incorporate: once started the emulsion will take much more. The stopping point is therefore an emotional rather than a chemical one.
Brittany claims this sauce for its own, though you will find it proclaimed as a local speciality throughout the Loire Valley. It goes beautifully with any simply cooked fish, whether poached or pan-fried. Muscadet works particularly well both in the sauce and to drink with the finished dish, while Brittany has no similar wine to offer. Who cares where it originated, it can be yours.
Peel and finely chop the shallots • Cut the chilled butter into 8 pieces.
Put the chopped shallots into the saucepan with the wine, vinegar and salt Bring to a fast boil then reduce to a simmer, stirring from time to time until all you have left is a mush of shallots and a film of residual liquid.
Take off the heat for a minute to allow the base to cool a little. Then put in 30g / 1 oz of the butter, place over a low heat and whisk vigorously until they combine and there is no visible element of butter.
Add the rest of the butter a piece at a time, adding the next piece as the last disappears into the sauce. After the last piece is just incorporated, remove from the heat and continue to whisk for 5-10 seconds. It will be creamy with a discernible body. Serve immediately.
With practice you will find you can add much larger pieces of butter after the first lump has emulsified. The first time you cook it, however, go more slowly and remember always to keep the heat under the pan low.
© 1993 Alastair Little. All rights reserved.