Ingredients

1 egg yolk

1/2 c minced watercress leaves

1/4 c chopped scallions

Juice of one lime (zest before juicing)

1 T Dijon mustard

1/2 t salt

Pepper to taste

3/4 c olive oil

2 t grated lime zest

Preparation

Combine all ingredients except oil and lime zest in food processor. Process until smooth. Add oil gradually, processing constantly until thick and smooth. Mix lime zest by hand in bowl. Chill.