Wash, peel and coarsely grate the potatoes and sprinkle with lemon juice. Peel and finely chop the onions. Clean, wash and dice the peppers. Cut sausage into slices. Cream fat, stir in eggs bit by bit. Add milk, mix everything and season with salt and pepper. Mix flour and baking powder, sieve onto the fat egg mass and mix.
Fold the grated potatoes and half of the onions into the dough, place on a greased baking tray, smooth it down and pre-bake in the preheated oven (electric cooker: 200 °C / gas: level 3) for about 15 minutes. In the meantime, heat oil in a pan and fry the remaining onions while turning. Add the sauerkraut and braise over medium heat for approx. 5 minutes, add the paprika and sausage and braise for another 5 minutes. Whip cream until half stiff, fold in sour cream, season with salt, pepper and paprika. Take the cake out of the oven. Spread the sauerkraut evenly on top, spread the cream and sour cream mixture over it, sprinkle with some paprika and bake for another 25 minutes. Cut the cake into pieces and serve pieces as desired, garnished with a dash of sour cream, paprika and parsley