One good recipe for slow cooker cabbage soup is cabbage soup with tomatoes, sausage and Parmesan. Spicy sausage, and fresh grated Parmesan cheese add a lot of flavor to this dish.
To make the soup, chop 1 pound of cabbage, 1 small onion and 1 cup of celery. Place the chopped ingredients in a slow cooker, and add 2 14 1/2 ounce cans of diced tomatoes, 6 cups of beef stock, 2 teaspoons of dried thyme, 1 teaspoon of ground fennel and fresh ground pepper to taste. Cook for eight to nine hours on low or three to four hours on high.
Then, slice 4 to 6 links of flavorful sausage such as chicken-garlic sausage. Heat 2 teaspoons of olive oil over medium-high heat, and cook the sausage slices until they browned on both sides. Add the sausage to the soup, and cook on high for 35 to 40 minutes. Serve this soup hot with freshly grated Parmesan cheese on top. To make this a vegetarian recipe, use tofu or vegetable sausages and substitute vegetable broth for the beef broth. Alternatively, chop all of the ingredients for this dish the night before cooking, and put them in the slow cooker in the morning.