Rinse the potatoes and steam for 30 minutes. Rinse the celery, coarsely chop the leaves and set aside. Cut the celery stalks into thin slices. Blanch the celery for 1-2 minutes in salt water. Rinse with cold water and drain. Hard-boil the eggs for 10 minutes. Peel the eggs and chop. Mix the whipping cream, vinegar, lemon juice and a little bit of water. Season with salt, sugar and pepper.
Peel the potatoes, allow to cool until lukewarm and slice. Mix the potaotes, celery, celery leaves, eggs and dressing. Season to taste and serve.