Bercy Sauce for Seafood

Bercy, a beautiful arrondissement, or district, in Paris gives its name to this delicious sauce served with fish and seafood dishes. Usually known as Bercy I, not to be confused with Bercy Sauce II, it's made by reducing white wine and chopped shallots, which is then mixed with a basic fish velouté and left to simmer until silky and reduced to perfection. (Bercy II is a sauce made from a basic demi-glace rather than a fish velouté, and thus is served with roasts and steaks instead of fish.) Bercy I doesn't take long and is fairly simple if you already have prepared fish velouté at hand. These measurements make about one pint of sauce, or enough for 8 guests.

In French cuisine, there are five mother sauces from which other sauces are made. Espagnole, velouté, hollandaise, béchamel, and tomato are the key sauces. They are all made with a roux, except hollandaise sauce, and the differences lie in the liquid into which the roux is dissolved as well as the seasoning and/or vegetables that are part of the mixture. Espagnole sauce is simmered with veal or beef stock and velouté with fish, vegetable, or chicken stock. Tomato sauce is based, you guessed it, on roux and tomatoes, while béchamel is made with roux and dairy—milk or cream. Roux-less hollandaise is made with egg yolks, clarified butter, and lemon juice or white wine. All delicious, they all serve different purposes, like bechamel adding creaminess to a Croque madame, or velouté making the base to a mushroom gravy, a seafood bisque, or in our case Bercy sauce.

This is the perfect sauce for baked, poached, or broiled fish, as its subtle flavor and delicious creaminess complement all types of seafood beautifully such as salmon, sole, sauteed soft shell crabs, shrimp, or lobster. We use the classic addition of parsley, but there are many variations out there that replace it with the stronger-tasting tarragon. As Bercy sauce contains dairy from the fish velouté, it is a highly perishable sauce, so if you don't need a whole pint perhaps it's best to cut the ingredients by half and just make a smaller amount. If you do have leftovers, refrigerate them in an airtight container for 2 to 3 days and don't consume any beyond that point. Reheat to a boiling point, constantly mixing, and never re-store whatever you've already reheated.