Please include direction to work quickly and not to overheat mixture as sauce is likely to ?break,? separate.
In a saucepan combine vinegar, wine and shallots. Over low to medium heat reduce mixture to about 1 tablespoon of product. Mixture will become like a jam.
Over low heat add dots of cold butter while continually whisking. Continue to add, mount, butter quickly, barely allowing for previously added butter to melt. Mixture will appear frothy and creamy.
Strain sauce (optional). Season with salt and pepper to taste Serve over steamed asparagus