Add all ingredients to Instant Pot and stir well to combine. Cook on High Pressure for 24 Minutes, and then allow to sit on 'Warm' setting for at least an hour afterwards. Shred chicken breasts right in the Instant Pot, and then stir well. Serve soup over a bed of broken up Tortilla chips and top with shredded cheese and sour cream. Guacamole is great too!