6 tbsp. butter
3 c. sliced leeks
3 potatoes, peeled and cut into chunks
13 1/2 oz. can chicken broth
1 c. water
2 bunches watercress, thoroughly rinsed
1 c. light cream
3 egg yolks
1 c. heavy cream
1 tsp. salt
Pinch of ground red pepper
2 tbsp. dry Vermouth
2 tbsp. dry sherry

In a large saucepan, melt butter over medium high heat. Stir in the leeks and saute until soft. Add the potatoes, broth and water. Bring to the boil, lower heat and simmer 25 minutes, or until potatoes are soft.

Remove from heat, stir in 1 bunch watercress and stir until cres wilts. In a blender, puree potato-watercress mixture with 1 cup light cream. (Process in small batches to avoid stringness from watercress.

In medium size bowl lightly beat egg yolks. Gradually stir in 3 cups of puree. Stir in heavy cream. Add yolk mixture and the remaining puree to a large saucepan. Stir in salt and ground red pepper. Gradually heat but do not boil. Stir in Vermouth and sherry. Garnish with remaining watercress leaves. Serve warm or chilled.