First peel the celery, wash it and cut it into cubes. Then sauté in the butter. Then dice the onion, add to the celery and sauté. Pour in the stock and simmer for 15 minutes. Then puree the soup and strain it through a sieve. Bring to the boil again, stir in the cream and season with salt, pepper, lemon and a little nutmeg.
Now chop the dill and cut the salmon into bite-sized pieces. Sprinkle both in the soup for serving.
Tastes excellent and celery is said to have some other desirable properties;)