Pour leftover chicken into pressure cooker on bottom. Drain can of corn and dump this in on top.
Drain and rinse can of black beans, dump that in. Sprinkle in uncooked rice on top. Pour in water and broth followed by salsa. Use the back of a spoon to gently submerge rice on top into liquid below, do not stir.
Sprinkle with salt and pepper. Close lid and seal steam valve. Cook on high pressure for 6 minutes with a 8 minute natural release. Release rest of steam.
Lift lid, fluff rice and mix contents gently. Sprinkle top with cheese and set lid on to melt.
Serve topped with slices of avocado and a dollop of sour cream on top.