|Peppercorns||6 , crushed|
Boil vinegar, peppercorns, chopped shallot and bayleaf together until liquid is reduced to 2 tablespoons, strain.
Beat egg-yolks lightly in top of double boiler and stir in strained liquid.
Gradually beat in cooled melted butter and stir continuously over simmering water until thickened.
Season with salt and pepper.