avocado slices, sour cream, tomato and cilantro for garnish, optional
Add all ingredients except corn to the Instant Pot. Stir to combine.
Lock on lid and turn vent to "Sealing". Set Instant Pot to Pressure Cook - High Pressure. Use the (+/-) buttons to manually set cook time to 12 minutes. When cooking is done, allow Instant Pot to natural release for 5 minutes, then carefully turn vent to "venting" and let remaining steam to vent. Carefully open lid.
Remove the cooked chicken breasts from the Instant Pot and shred into bite size pieces. Return the shredded chicken to the pot and stir to combine.
Ladle soup into bowls and top with avocado slices, sour cream, chopped tomato and cilantro.
Store leftovers covered in the refrigerator for up to 3 days or freeze for up to 3 months.