1 bunch watercress
1 tbsp. butter
2 c. chicken broth
1 egg yolk
1 c. heavy cream
1/2 shallot, minced
1 tbsp. flour

Discard stems from watercress and mince leaves. Melt butter in saucepan, add shallot; saute briefly and add flour, blending well. Add watercress. Add the chicken broth and heat to simmer. Beat egg yolk and cream together. Add some of the hot broth to the yolk/cream mixture, then whisk cream into soup. Heat thoroughly, but do NOT boil.