Clean, peel, and chop vegetables. Roughly dice onion. Form little meatballs out of sausage and fry in rapeseed oil until brown. Remove from the pot.
Fry onions, celery, carrots, and parsley root in same pot. Add half of the stock and cook on low heat for approx. 15 min.
Add leek, Savoy cabbage, and the second half of the stock. Cook for approx. 5 min. Cook pasta at the same time.
When pasta is al dente, drain and add to the large pot. Add sausage, herbs, soy sauce, and lemon juice, cook briefly and season to taste. Done!