In a stockpot over medium heat, heat the olive oil. Sauté the onions and garlic for about 4 minutes. Add the chicken breasts and sauté until they breasts until they are cooked all the way through. Using a wooden spoon and some of the chicken broth, deglaze the pan as you cook the chicken.

Put the chicken and any juices into a slow cooker. Add the rest of the ingredients--except for the cream cheese--and stir well. Cover and cook for 8 hours on low (4 on high) With one hour to go before finishing, take the chicken out and shred the meat. Return the meat to the crock pot, cover, and cook for the last hour.

Once the soup is done, scoop out 1 cup of broth and stir it in a bowl with the cream cheese. Stir until the cheese is melted and return to the crock pot. Heat for another 15 minutes and serve with tortilla chips and avocado slices.