Iced Cucumber Soup

1 small onion, diced
2 cucumbers (unpeeled), chopped
Butter
1 cup light cream
1/8 tsp. thyme
Salt and pepper
4 cups homemade chicken broth
Chopped fresh tarragon
2 egg yolks
6 - 8 lemon slices
Toasted sliced almonds
Sour cream

Saute onion and cucumbers in a small amount of butter until tender. Stir in cream, thyme, salt and pepper to taste. Simmer five minutes. Put three cups of the chicken broth in a pot. Using the back of a spoon, force the cucumber mixture through a sieve into the broth. Add tarragon and heat. Beat egg yolks with the remaining cup of cool broth. Slowly pour 1/2 cup of the hot broth mixture into egg yolk mixture, beating briskly. Add another 1/2 cup, still beating. Stir egg yolk mixture into pot with other ingredients and allow to thicken over lowest heat, stirring constantly. Do not boil. Cool, then chill. Garnish each cup of soup with a lemon slice, almonds, and one teaspoon sour cream. Serves six to eight.