Beurre blanc is a very simple emulsified butter sauce that uses wine, vinegar and shallots and works well with virtually any seafood. The ginger beurre blanc can be used as a substitute for the butter sauce in the recipe above. If you also want to add a garnish of julienned fennel and/or ginger to the final dish, you can sauté them with some sliced garlic in the clarified butter or extra-virgin olive oil as described above.
1 cup of dry white wine
1/2 cup of white wine vinegar
2 tablespoons of finely minced shallots
1 tablespoon of finely grated fresh ginger
1 pound of cold unsalted butter, cut into 1 tablespoon pieces (keep in the refrigerator until ready to use)
Heat the wine, vinegar, shallots and ginger in a heavy sauce pan until it comes to a boil, then reduce to a simmer. Continue cooking until the wine and vinegar are reduced to about 2 tablespoons, approximately 8 to 10 minutes. Reduce the heat to low and whisk in the butter, one piece at a time. (It is important to watch the temperature of the sauce. It is quite delicate and will break or look curdled if it is kept over direct heat for too long.) Add the next piece of butter just before the previous one has fully melted and continue to whisk until all of the butter has been incorporated. The sauce should be thick and creamy. Remove from the heat and strain. You can return the beurre blanc to a clean heavy pan and keep it warm for several minutes over very low heat. You can also keep it warm for about 1/2 hour by placing it in a container in hot, but not simmering, water; or pour it into a small thermos and screw the top on. The thermos will keep the beurre blanc warm for an hour or more.