The night before you plan to serve this soup, pour the beans into a large saucepan, cover with water and bring to a boil, lower the heat and simmer for 30 minutes. Reserve the seasoning packet for later. Let the beans cool in the water and then refrigerate overnight. Drain the beans and rinse. Put into a slow cooker along with the reserved seasoning packet.
Heat a large skillet over medium heat and add the sliced sausage, onions and carrots. Cook until everything starts to brown, about 10 minutes. Add the garlic and cook for 30 seconds. Season with salt and pepper. (Can be made up to this point the night before, put in an airtight container and refrigerate.) Put in slow cooker with the beans and add the rice, stock and water. Stir everything to combine. Cook on low for 8 – 10 hours. Garnish soup with green onions.