Cover the beans with water and soak over-night. Drain.
Using a mortar and pestle pound together the lemon rind, garlic and caraway seeds to make a paste.
Season the flour with salt and pepper, add half the paprika and coat the meat cubes with the flour mixture.
Heat the oil in a large cast-iron pot and brown the meat in small batches.
Add the lemon paste, tomato paste, onions, red pepper and the remaining paprika. Add the stock and simmer for 30 minutes or until the meat is nearly tender.
Add the soaked beans and simmer for another 25 minutes over medium heat. Add more water if necessary.
Ladle the soup into bowls or mugs with large dollops of sour cream and fresh farm bread.