In a microwave safe bowl, add onions, celery, red bell pepper and garlic. Cook about 3 minutes until the veggies are soft.
To cook in crock pot: Add cooked vegetables, chicken, chicken broth, enchilada sauce, beans, tomatoes and corn. Mix well. Cook on low 4 hours or on high 2 hours.
To cook on stove top: In a large soup pot, add cooked vegetables, chicken, chicken broth, enchilada sauce, beans, tomatoes and corn. Mix well. Bring to a boil, cover, turn down to simmer and cook covered for 30 minutes.
To serve: Ladle almost 2 cups soup in each bowl. Top with any or all of the optional toppings, if desired. I like to add 1 tablespoon of scallions, cheese, yogurt and crushed tortilla chips to mine. Serve with salsa on the side, if desired.