Bearnaise sauce is a classic French sauce made with a reduction of vinegar, white wine, tarragon, black peppercorns and shallots. It's finished with egg yolks and butter. Delicious served with any plain meat or fish.
Bearnaise is a sauce is a variation of hollandaise sauce. It is not like a bechamel sauce at all. A reduction of white wine and seasonings is blended with egg yolks until emulsified. Traditionally, the sauce is seasoned with shallots and tarragon.
Bearnaise which can also be spelled Bernaise, is a French term pronounced "bair-naz"