1. Combine the finely chopped Shallots with the White Wine and Vinegar in a heavy-bottomed saucepan. Gently simmer the mixture until practically all the liquid has evaporated (reduced by 90%).

2. Add Heavy Cream. (If the cream is not being used, the same amount of another liquid, such as water, must be added, or the sauce will be too thick.)

3. Check the inside of the saucepan to make sure it has not browned, which would discolor the sauce. Wipe off any browning with a wet towel.

4. Cut the butter into 1-inch cubes, and add them to the shallot infusion. Whisk the sauce over medium heat until all the butter has been incorporated.

5. Adjust the seasoning. If the sauce seems flat, add wine vinegar, a few drops at a time. If the sauce tastes harsh or overly acidic, whisk in more butter.

6. Many chefs prefer to strain the beurre blanc, but for some dishes the minced shallots provide an appealing contrast to the pale sauce.

This recipe contains a small amount of heavy cream, which, although not essential, will help start the emulsion. A great deal of myth still surrounds the addition of the butter to the flavor base. Many authors insist that the butter be added in tiny increments, often as little as a tablespoon at a time, over low heat and imply that the sauce will break if the butter is added any faster. In fact, the butter can be cut into relatively large cubes (about one inch on each side) and added all at once over high heat. The keys are not to stop whisking and not to let the sauce boil. Seasoning should be added at the end.

HOLDING AND SAVING BEURRE BLANC: If held properly, beurre blanc prepared just before a restaurant service or lenghty meal will stay intact for several hours.. Leave it in the saucepan, covered in a warm area such as a warm oven, plate warmer, or on the back of the stove. If necessary, the saucepan can be placed in a pan of hot water. When beurre blanc is held for any length of time, it will begin to thicken and must be thinned periodically with heavy cream, water, court-bouillon, or another appropriate liquid. If it is not thinned and stirred approximately every thirty minutes, it is likely to break. Broken beurre blanc can be repaired by whisking it into several tablespoons of reduced heavy crem, but this can be done only once.

VARIATIONS: You can add Orange, Lemon, or Grapefruit zest with the shallots and a teaspoon of juice for a citrus sauce. Adding finely grated fresh Ginger Root will give it a spicy, oriental flavor.