Soak the dried mushrooms in warm water for about an hour. After they're rehydrated, drain and chop them.
In a large pot, heat the oil or lard over medium heat. Add the finely chopped onions and sauté until translucent. Add the minced garlic and sauté for another minute.
Add the sliced smoked sausage or klobasa, and roughly chopped pork shoulder to the pot and let it brown lightly. The meat should be u0022closedu0022 from all sides.
Sprinkle in the paprika, black pepper, caraway seeds, and bay leaves. Stir well to coat the sausage the meat, and onions.
Add the drained sauerkraut and chopped mushrooms to the pot. Mix well.
Pour the beef or vegetable broth into the pot. Bring the mixture to a boil, then reduce the heat to low, letting it simmer for about 30-40 minutes.
Taste the soup and adjust the salt as needed. Kapustnica should have a pleasant balance of sourness from the sauerkraut and smokiness from the sausage.
Swirl in some sour cream just before serving (optional) for a creamy touch. Serve the soup hot, ideally with a slice of hearty rye bread on the side.
