Clean, wash and finely slice the white cabbage. Salt cabbage and mash well. Leave to soak. Mix 2 tablespoons of vinegar, caraway, pepper, sugar and parsley. Add 2 tablespoons of oil.
Pour the marinade over the cabbage and mix. Wash the potatoes and cook in boiling water for about 20 minutes. Drain potatoes, quench, peel and let cool. Cut potatoes into slices.
Cut bacon into small cubes and fry in 1 tablespoon of hot oil. Peel and chop the onions. Fry half of them briefly. Deglaze with broth and the rest of the vinegar. Pour marinade over the potatoes and mix carefully.
Season to taste with salt, pepper and sugar. Leave to soak for an hour. Soak the rolls in cold water. Wash the fish, cut into pieces, sprinkle with lemon juice and chop finely in a universal chopper.
Knead the fish, remaining onion, egg and squeezed bread roll. Season to taste with salt and pepper. Form 8 meatballs from the fish mixture and turn them in breadcrumbs. Heat the remaining oil in a pan and fry the meatballs at medium heat for about 8 minutes.
Arrange the fish cakes with the potato salad on a plate. Garnish with lemon and parsley. Serve with the white cabbage salad.