Béarnaise sauce (French: Sauce béarnaise) is a sauce made of clarified butter emulsified in egg yolks and flavored with herbs. It is considered to be a 'child' of the mother Hollandaise sauce, one of the five sauces in the French haute cuisine mother sauce repertoire. The difference is only in their flavoring: Béarnaise uses shallot, chervil, peppercorn, and tarragon, while Hollandaise uses lemon juice. Its name is related to the town of Béarn, France.
In appearance it is light yellow and opaque, smooth and creamy.Béarnaise is a traditional sauce for steak.