Berner Sauce - cooking recipe

Ingredients

4 Tbsp. white wine
3 Tbsp. wine vinegar
1 clove
3 shallots
1 small stem tarragon
1/2 bay leaf
salt
peppercorns
2 egg yolks
10 Tbsp. butter

Preparation

Bring wine, vinegar and spices to a boil.
Strain.
When cool, stir in egg yolks and half the butter.
Place in double boiler over hot but not boiling water and gradually add remaining butter, beating constantly until thick.