Place chicken breasts in the bottom of the Instant Pot.
Add water, onion, corn, black beans, salsa, lime juice, taco seasoning, and dry ranch mix.
Place the lid on to of pot and move valve to SEALING (not venting).
Press the PRESSURE COOK (or MANUAL) button and set timer for 20 minutes (or 25 minutes if using frozen chicken breasts).
When cook time is finished, do a QUICK RELEASE of the pressure.
Remove the chicken from the pot and shred using 2 forks.
While the chicken is out of the pot, add in cream cheese and pepper jack cheese.
Mix together until all the cream cheese and pepper jack cheese is melted (if you want, you can press the SAUTE button to heat it up faster) and the mixture is creamy.
Add the chicken back in and stir.
Use this chicken for tacos, burritos, nachos, salads, enchiladas, quesadillas, etc. The possibilities are endless!