Step 1

Heat the oil in a large skillet over medium-high. Add the brisket pieces, and cook, turning to brown on all sides, about 8 minutes. Place the brisket pieces in a 4- to 6-quart slow cooker. Add the onions, thyme, and garlic to the skillet, and cook, stirring often and scraping to loosen the browned bits from the bottom of the skillet, about 4 minutes. Add the caraway seeds and crushed red pepper; cook 30 seconds. Add the tomato paste and 2 cups of the stock to the skillet; stir to combine, and bring to a boil. Add the onion mixture to the slow cooker. Stir the beets, parsnips, rye berries, salt, and remaining 4 cups stock into the slow cooker. Cover and cook on LOW until the brisket is tender, 7 hours and 30 minutes.

Step 2

Remove the brisket pieces, and set aside. Add the cabbage and red wine vinegar to the slow cooker; increase the heat to HIGH, and cook, uncovered, just until the cabbage is wilted, about 15 to 20 minutes.

Step 3

Meanwhile, shred the brisket using 2 forks. Add the shredded brisket and black pepper to the slow cooker, and stir to combine. Ladle the soup into bowls. Top evenly with the sour cream and dill.