This is the perfect soup for this time of year, almost spring.
In a large soup pot with some olive oil, sauté a chopped shallot, a minced clove of garlic and a chopped head or two of celery -- leaves and all. Give it about 10 minutes and then add ¼ teaspoon of black pepper and enough chicken stock to cover the celery by about 1 inch. As always, the better the stock, the better the soup.
Simmer for approximately 30 minutes or until the celery is very soft and then puree using a stick blender or transfer to a food processor.
Put the soup back on low heat and stir in 1 or 2 cups of grated parmesan. It depends on how much soup you made, but it’s hard to add too much. To finish, salt to taste.