Add all of the ingredients starting from the chicken breasts and stopping at the chicken bouillon cubes to a large crockpot. Cook on low for 6-8 hours. At the end of the cooking time, use two forks to shred each one of the chicken breasts until they are all shredded. I shred the chicken breasts while they are still in the crockpot, but be careful. It will be hot. You can also take the chicken breasts out of the crockpot and shred the meat on a plate. If you choose this method, make sure to not only add the shredded chicken back into the crockpot but also include any juice which might have seeped out onto the plate. Add the juice of one lime and stir. Add 1/2 cup sour cream and stir. Heat another 15 minutes or so ensuring the sour cream is heated through in the soup. Serve hot with cilantro and tortilla strips as toppings.