A Bearnaise Sauce is simply made with clarified butter egg yolk a little tarragon white vinegar white wine. It takes years of practice for the result to make it perfect
Combine vinegar, wine, pepper, scallions and tarragon in saucepan. Cook over low heat until reduced to half, about 8 minutes. Strain mixture into top of double boiler. With wire whisk or rotary beater, beat in beaten egg yolks and salt. Cook over hot water until thickened. Beat in butter, 1 tablespoon at a time. Stir over heat till creamy, about 1 minute.
Serve hot over beef or fish fillets.