Great on seafood! From epicurious.com
2 cups dry white wine
1/2 cup white wine vinegar
2 shallots, minced
1/2 cup whipping cream
4 tbsp vegetable oil
1/2 cup chilled unslated butter, sliced into 8 pieces
1 cup coarsely chopped fresh cilantro
Boil wine vinegar and shallots in heavy medium saucepan until liquid in reduced until, about 18 minutes. Add cream and boil until sauce coats spoon, about 3 minutes. Bring sauce to simmer, remove from heat. Add butter one piece at a time, whisking until just melted. Add cilantro, blend until cilantro is just minced, about 10 seconds. Add salt and pepper to taste.
Makes about 6 servings.
Sauce can keep (covered) 1 day in fridge