Cold Avocado Soup

Directions

1. 1
   Heat the butter in a saucepan over moderate heat and stir in the flour.
2. 2
   Cook for 2 to 3 minutes, stirring frequently. Add the chicken stock and bring to a boil, stirring frequently.
3. 3
   Boil for 5 minutes, remove from the heat and allow to cool to room temperature.
4. 4
   Peel and pit 3 of the avocados and combine them with the remaining ingredients in an electric food processor or blender. Add about 2 cups of the cooled chicken stock and puree until smooth.
5. 5
   Pour the avocado mixture into the saucepan with the remaining chicken stock and stir to combine.
6. 6
   Chill for at least 2 hours.
7. 7
   Immediately before serving, peel, pit, and dice the remaining avocado.
8. 8
   Serve garnished with the diced avocado and a dollop of sour cream if desired.