Slow Cooker Spicy Cabbage Beef Soup is full of browned ground beef, onion, cabbage and tomatoes. It’s a simple soup, but with so much flavor, plus it’s low carb.This is a great "set it and forget it" meal. Imagine walking into the house after this has been simmering in the slow cooker all day. Grab a bowl, maybe some fresh crusty bread and you have a meal.