Bearnaise is a sauce made of clarified butter and egg yolks flavored with tarragon and shallots, with chervil and tarragon simmered in vinegar to make a reduction. "A bearnaise 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) in Ma Gastronomie. It is a traditional sauce for steak. It is ment to be served on a chateaubriand roast. It is one step from mayonnaise.