Melt the butter or margarine in a large saucepan and fry (saute) the
onion, carrot, celery and garlic until soft but not brown. Add the stock
and chicken and bring to the boil. Simmer for about 10 minutes until the
vegetables are very tender. Add half the parsley and season to taste with
salt and pepper. Puree the vegetables in a food processor or blender,
adding enough of the stock to make a thick soup. Return to the pan, add
the cream and adjust the seasoning to taste. Reheat gently and serve
sprinkled with the remaining parsley.