Drain the sauerkraut. Heat the butter and fry the sausage slices in it for about 5 minutes and remove them. Steam the onion strips in the frying fat until translucent, add the sauerkraut and dust with paprika and flour. Pour in the broth and add the tomatoes. Bring everything to the boil and then simmer for about 4 minutes. Season the goulash with salt, pepper and ground caraway seeds.
Serve the dish with dumplings or potatoes and a dollop of sour cream.