Serves 8 to 10
• A lovely soup for a big party, but the proportions can easily be cut in half.
• ½ cup butter
• 1⅓ cups chopped onions
• 6 Tbs. flour
• 9½ cups hot Potato Peel Broth
• 6 packed watercress leaves, washed
• 1 cup heavy cream
• 4 eggs
• 2 Tbs. lemon juice
• 1 Tbs. sugar
• salt to taste
• pepper to taste
1. Melt the butter in a large pot and sauté the onions in it until they just begin to turn golden. Stir in the flour and lower the heat. Cook the roux, stirring constantly, for a few minutes. Continue stirring as you gradually add the hot broth. If you detect any lumps forming, stir briskly with a whisk.
2. Add the cleaned watercress leaves and simmer the soup for about 10 minutes. Taking the soup in batches of several cups, purée it in a blender until it is perfectly smooth. Return the soup to the pot.
3. Beat together the cream and the eggs, and continue beating as you pour in about 2 cups of the hot soup. Stir this mixture back into the soup, off the heat. Season the soup with the lemon juice, sugar, salt, and pepper.
4. Over a moderate flame, stir the soup for about 3 to 4 minutes, or until it is quite hot through but not simmering. Serve immediately.
