Cream of Celery Soup

1 bunch celery (dark leaves removed)
2 medium potatoes (peeled and quartered)
1 onion (skinned, quartered)
3 tbsp butter
1 litre chicken stock
250 ml cream
salt and pepper to taste

1. Cut the celery into larger sized diced pieces. Put the celery and onion in a food processor and process until well chopped. You want to ensure there aren't any stringy bits in the finished soup.
2. In a large pot, heat butter and add pulverised celery and onion.  Stir gently over medium to low heat, carmelising the onion.
3. Add the potato, stock and seasonings.
4. Bring to boil, reduce heat to simmer, and cook for about 20 minutes or until potato is breaking up. Using a stab blender or goblet blender, puree the soup until smooth. 5. Add cream and gently heat, but do not boil, taste and adjust seasonings.