Peel and slice the parsley root. Chop shallot. Suate the parsley root with shallot in the butter, not frying. Pour the broth, wine, add chopped garlic, salt and cook on low heat for 20 minutes. Add the cream, blend the soup in a light puree. Cast a 2/3 of the soup, add parsley in the remaining part of the soup, blend again, mix the green part with white and serve.