Classic French sauce made with a reduction of vinegar, wine, tarragon and shallots and finished with egg yolks and butter. Served with meat, fish, eggs, and vegetables.
Bearnaise sauce (French: Sauce Béarnaise) is a sauce of butter and egg yolks flavored with tarragon and shallots, with chervil, cooked in wine and vinegar to make a glaze. "A Béarnaise sauce is simply an egg yolk, a shallot, a little tarragon vinegar, and butter, but it takes years of practice for the result to be perfect," wrote the restaurateur Fernand Point (1897-1955), the father of modern French cuisine, in Ma Gastronomie. It is a traditional sauce for steak.