Saint Paddy's Leprechaun Green Sauce

Source: Michael Marks - Your Produce Man

2 tablespoons lemon juice
1/4 cup chopped parsley
3/4 cup lightly packed rinsed and drained watercress sprigs
1 tablespoon chopped tarragon
1 cup sour cream (or half sour cream and half plain yogurt)
Salt

In a blender or food processor, combine lemon juice, parsley, watercress, tarragon, and sour cream. Whirl until mixture is smoothly puréed, scraping container sides as required.

Serve over potatoes.