I love Brussels sprouts and this is very tasty.
Melt butter; cook onion and potato 2 to 3 minutes. Add sprouts; cook 5 minutes, stirring constantly. Sprinkle in flour; blend well. Pour on stock; stir until well mixed and smooth. Bring to boil; stir constantly. Reduce heat. Add bay leaves, parsley, and seasoning, cover. Simmer about 20 minutes, until vegetables are tender but not overcooked, as this would give soup an unpleasant flavor.
Remove bay leaves. But soup through food processor; blend until smooth. Adjust seasoning; reheat soup. At last moment add cup of hot cream. Sprinkle with chestnut pieces, fried in butter until golden brown.
Source: Creative Cooking
By Raymonde from North Bay, Ontario