2 tblspns tarragon vinegar
2 tblspns water
6 crushed peppercorns
1 tblspn chopped shallots
3 egg yolks
125 g butter
Combine vinegar, water, salt, peppercorns and shallots in small saucepan.
Heat until liquid is reduced to about 2 tblspns; remove from heat, strain, reserve liquid.
In top of double saucepan beat egg yolks lightly, stir in strained liquid.
Place over simmering water, gradually beat in the butter, a small piece at a time.
Beat until all butter has been added and sauce thickens.