Hollandaise

The most reliable method for hollandaise is to make a mousse by whisking egg yolks with water (a tablespoon per yolk), over heat, directly or in a double boiler. The process should take at least three minutes, by which time the mousse should be light but close-textured. The mousse acts as a stabilizer so that melted butter can be added without the sauce separating. Other methods of making hollandaise, for example by heating egg yolks and cold butter in a water bath, are slower and more difficult to master.