STOCK: Rinse chicken thoroughly, place in a saucepan with water, celery, onion, carrots, bay leaf, salt and peppercorns.
Bring to boil. Skim, cover and simmer for 1 1/2 hours. Remove from stove, strain and skim off fat.
If stock is not concentrated enough, boil, uncovered, to reduce further.
SOUP: Melt butter in a heavy-based saucepan. Add onion, cover and sauté over gentle heat until translucent.
Add vegetables and sugar and cook for 10 to 15 minutes, stirring occasionally, or until vegetables start to soften and butter is absorbed.
Sprinkle flour over and stir in to blend. Gradually add stock, stirring constantly. Stir in ginger.
Bring to boil, then turn down heat and add milk, orange peel, curry powder and seasoning. Simmer for 10 to 12 minutes.
Remove and purée in a food processor, using steel blade. Add seasoning and heat until piping hot.
Serve topped with a dollop of thick cream and sprinkled with parsley.