In a heavy bottom pan, heat the butter and fry the shallot, garlic and celery for about 10min till translucent.
2
Add flour and milk and cover with water, add salt and pepper and cook for 15min, uncovered. When the celery is cooked, strain the soup through a sieve.
3
In each plate place a spoon of sour cream, pour the soup over and sprinkle with few drops of lemon. Decorate with celery leaves.