Peel carrots, celery, parsley roots and onion. Leave some green on the carrots. Chop the celery and parsley roots roughly. Cook the vegetables in boiling salted water for about 5 minutes. Drain.
Dice onion. Fry in 1 tbsp. hot butter, deglaze with vinegar and simmer for about 5 minutes. Heat the rest of the butter in a pan. Fry the celery root mix in portions for about 5 minutes. Fry the carrots for about 3 minutes.
Add all vegetables again, sprinkle with 1 tablespoon of sugar, caramelise. Season with salt and pepper.
Clean and wash the spring onions and parsley. Cut onions into rings and chop parsley roughly. Mix with oil, lemon juice and zest. Arrange on the vegetables with the balsamic onions.