Kapustnica (Slovak Christmas sauerkraut soup)

Instructions

1. Soak the dried mushrooms in lukewarm water for 20 minutes, then drain them and slice them thinly, keeping the soaking water.
2. Sauté the sliced onion in the oil, then add the ham hock, carrots and celery cut into small cubes.
3. Add the rinsed sauerkraut, the strained soaking water, the mushrooms, the bay leaves and the water, then bring to the boil.
4. Simmer covered for 60 minutes over low heat.
5. Mix the flour with a little cold water, then pour it into the soup, stirring to thicken.
6. Add the paprika, the marjoram and the sausage cut into rounds, then cook for another 20 minutes.
7. Adjust the seasoning with salt and pepper, then serve piping hot with rye bread.