Peel and halve the celery and cook in salted water for about 20 minutes. Take it out with a ladle, quench cold and let it cool down. Cut into thin slices with a colored knife. Peel onions and cut them into fine rings. Bring vinegar, 100 ml vegetable stock, bay leaves and peppercorns to the boil.
Add onions, season with sugar and let cool. Chop dill finely and add to the vinegar stock with the oil. Leave celery slices to marinade for at least 2 hours. Arrange pickled vegetables with salad leaves on 4 starter plates