Crockpot Chicken Taco Soup

This soup is DELICIOUS.  And so easy!

1 medium onion, chopped
1- 15 oz. can chili beans, undrained
1- 15 oz. can black beans, undrained
1- 16 oz. bag frozen corn
1- 8 oz. can tomato sauce
16 oz. (2 cups) chicken broth
2- 10 oz. cans diced tomatoes with green chilies, undrained
1- 1.25 oz. package taco seasoning
3 skinless, boneless chicken breasts
Shredded cheddar cheese
1 avocado
Crushed tortilla chips

Place the onion, beans, corn, tomato sauce, broth, tomatoes and seasoning in a slow cooker and stir to blend.  Add the chicken breasts.  Set the slow cooker on low, cover, and cook for 5 hours.  Remove chicken breasts from soup, shred the chicken, return to soup and cook for another hour.  Serve topped with cheese, avocado and chips.