Wash the celery and cut into strips with the celery greens, dice the onions, heat the chicken stock or water.
Steam the onions in butter or oil until translucent, add the celery and cook for approx. 8 minutes. Add the parsley and pour in the hot broth (or water), cook in a closed pot for approx. 35 minutes.
Puree the vegetables with the hand mixer, whisk the egg yolks, cream and white wine together and alloy the soup, do not let boil any more.