Sauce Vénitienne (Tarragon and Green Butter Sauce for Fish)

Ingredients

• 4 décilitres tarragon vinegar
• 2 and a half spoonfuls chopped shallots
• 25 grammes chervil pluches
• 3 quarters of a litre Sauce Vin blanc
• 125 grammes Beurre vert
• 1 spoonful chopped chervil and tarragon

Instructions

1. Put 4 décilitres of tarragon vinegar with 2 and a half spoonfuls of chopped shallots and 25 grammes of chervil pluches, and reduce by two thirds.
2. Pass the reduction through muslin, twisting it lightly.
3. Add it to 3 quarters of a litre of Sauce Vin blanc.
4. Complete with 125 grammes of Beurre vert and 1 spoonful of chopped chervil and tarragon.
5. Serve with fish prepared in various ways.