Lightened Beurre Blanc

If cold butter is whisked into too large a proportion of hot liquid, it will separate after a few minutes and end up as oil floating on top. For this reason, the obvious method of using more liquid as the base for a beurre blanc doesn’t work. A better way to lighten a beurre blanc—beurre blanc can be kept in a pan of warm water for up to a couple of hours before serving—is to combine it with a flavorful liquid, such as vegetable broth or fish broth, just before serving. The result is a butt