Add all ingredients, except toppings, to the bowl of a slow cooker. Stir and cook for 3-4 hours on high heat or 6-8 hours on low heat.
Ladle soup into bowls and garnish with toppings.
Note-the soup will keep in the refrigerator for up to 5 days. You can freeze the soup in a freezer container for up to 2 months. If you want to add chicken to this recipe, use two chicken breasts. Shred chicken with two forks when it is done cooking.