It's all about the quality of the chicken stock and you don't need a huge serving of this,
looks quite cute presented in a cup. Use more stock and less runny cream if you prefer. The lighter the pureed soup the better. It goes with our more minerally 2012 Riesling.
Use celery if you can't get celeriac. This is a very refreshing soup. It tastes good and is for you. I'd wilt celery leaves in the simmering stock then puree the leaves to swirl a darker colour through the soup for contrast.