1 egg yolk
½ T. lemon juice
½ T finely chopped onion
¼ c. firm butter
½ tea. dried tarragon leaves
½ T white wine vinegar
¼ tea dried chervil leaves
Stir egg yolk and lemon juice vigorously in 1 quart saucepan with wooden spoon. Add half of the butter (cut in small pieces). Heat over low heat stirring constantly until is melted. Add remaining butter. Cook stirring vigorously until butter is melted and sauce thickens. (Be sure to melt slowly as this gives eggs time to cook and thicken sauce without curdling). Stir in remaining ingredients.
(Great on steak, vegetables, and we use this rather than hollandaise on eggs Benedict as it has more flavor)