Green Sauce

Preparation info

  • Makes About

    450 ml

    • Difficulty


Appears in

A Feast of Fish

A Feast of Fish

By Ian McAndrew

Published 1989

  • About

This sauce makes a good accompaniment for any cold fish or shellfish, and it is also very good for serving with terrines. If the pronounced flavour of a particular herb, such as tarragon, is required, then increase the amount of tarragon and reduce the other herbs accordingly. Once made, the sauce should keep perfectly well in the refrigerator for a couple of days.


  • 50 g/2 oz potatoes
  • 120 ml/4 fl oz fish stock or water
  • 175 g/6 oz spinach
  • 50 g/2 oz fresh dill
  • 50 g/2 oz fresh parsley
  • 50 g/2 oz fresh tarragon
  • Salt and freshly ground white pepper
  • 1 egg yolk
  • 2 tsp Dijon mustard
  • 175 ml/6 fl oz salad oil
  • 85 ml/3 fl oz single cream


    Wash and peel the potatoes, then cut them up into small pieces. Cook them in the fish stock until soft. When cooked, allow them to cool in the stock. Pick the spinach of its stalks, and wash well. Pick all of the herbs of their stalks and add to the spinach. Cook the herbs and spinach in boiling salted water until just soft, then refresh in iced water and drain.

    Once cold, place all the cooked ingredients, including the potatoes, and a little salt and freshly ground pepper in a food processor or blender and process until smooth. Add the egg yolk and the mustard, and, with the machine on, slowly add the oil as if making mayonnaise.

    Remove the sauce from the machine, stir in the cream, pass through a fine strainer or muslin, then check the seasoning. If the sauce is a little too thick, it can easily be thinned down by whisking in a little water or fish stock.