Saute the onion in margarine covered for 5 min, without browning. Then add the carrots & ginger. Cover and cook for a further 10 min. Stir from time to time.
Add the stock or water and bring to a boil, then simmer gently for 15 min, until the carrots are tender. Puree the soup in a foodprocesor, then sieve (not really necessary).
Return the soup to the finsed out pan, reheat gently and season to taste with pepper.
(You may use parsnips instead of carrots and add 1 t. Curry powder to the onions when you saute them. A swirl of yogurt on top is good and add some crisp croutons.