Polish Pork and Sauerkraut Stew (Bigos)

Name: Polish Pork and Sauerkraut Stew (Bigos)
Cuisine: European, Eastern European
Ingredients: 1⁄4 oz. dried porcini mushrooms; 4 oz. bacon, cut into 1/2″ pieces; 1 lb. boneless pork shoulder, cut into 1″ cubes; Kosher salt and freshly ground black pepper, to taste; 8 oz. smoked kielbasa, cut into 1″ rounds; 1 tsp. caraway seeds; 8 whole allspice berries; 2 large yellow onions, chopped; 2 bay leaves; 1⁄2 cup tomato paste; 3 tbsp. flour; 4 lb. sauerkraut, drained; 2 oz. pitted prunes, chopped; 6 cups beef stock; 1⁄2 cup madeira wine; 2 medium tart apples, peeled, cored, and cut into 1/2″ cubes; Minced chives, to garnish