Bergen Fish Soup

Directions

1. 1
   Place the fish in the water and bring up to a boil. Let simmer for 1/2 hour. Filter this stock through cheesecloth.
2. 2
   Cut up the celery root, carrot, and leek into small pieces and cook in the filtered stock for 5-7 minutes. Remove the vegetables from the stock and put aside.
3. 3
   In a heavy pan melt the butter, add the flour and cook with stirring for 2-3 minutes. While continuing to stir add the stock to the butter-flour mixture and continue to cook until well-blended and smooth.
4. 4
   Mix together in a warm bowl the egg and the sour cream. Eventually add a little of the soup to this while stirring continuously. Continue to add up to 1 cup of the soup little by little until the egg-sour cream mixture has warmed through.
5. 5
   Carefully add this mixture to the remaining soup being careful not to let it boil. Add the resserved vegetables to the soup and serve, each serving to be topped with some of the chopped chives.