Clean and wash the kohlrabi, carrots and mangetouts. Dice the carrots and cut the kohlrabi into thin slices. Drain tomatoes on a sieve and collect the juice. Cut the tomatoes into quarters.
Peel onion and garlic. Chop the onion finely, press the garlic through a garlic press. Heat 20 g fat in a large pot. Fry the onion and garlic in it until transparent. Add carrots, kohlrabi and mangetouts and season with salt, pepper and thyme.
Add tomato juice and 11/2 litres of broth, bring to the boil, cover and cook for about 15 minutes. Add the tomato pieces after 10 minutes and bring to the boil. For the dumplings, bring the remaining stock and fat and a little salt to the boil.
Remove the pot from the hotplate. Sprinkle in polenta semolina and stir for 1 minute, until the mixture clumps together like a ball and comes off the bottom of the pot. Let the mixture cool down a bit, then stir in eggs and parmesan.
With 2 small tablespoons of dumplings, cut off and add to the soup. Bring the soup briefly to the boil again and let the gnocchi simmer for 5-10 minutes. Wash parsley, dab dry and chop. Season soup with salt and pepper, place in deep plates and serve sprinkled with parsley.