Slow Cooker Vegetable Tortilla Soup

Name: Slow Cooker Vegetable Tortilla Soup
Ingredients: 2 cups black beans ((this is 1 can + 1/4 cup) rinsed and drained); 14.5 ounces fire roasted diced tomatoes with juice; 10 ounces red enchilada sauce; 1 medium onion (chopped); 2 medium carrots (peeled and chopped); 4 stalks celery (chopped); 4 ounces diced green chilies; 4 cups water/vegetable broth; 1/3 cup chopped cilantro (+ more for garnish); 1 tsp ground cumin; 1 tsp chili powder; 2 cups frozen corn; mozzarella cheese for garnish (optional and not included in calorie count); avocado for garnish (optional and not included in calorie count)