In the insert pot of the Instant Pot, place chicken breast pieces. Add in sliced carrots and celery.
Pour chicken broth into the pot.
Add the frozen noodles into the pot.
In a large measuring cup or small mixing bowl, whisk together cream of chicken soup, water, and chicken base.
Pour the mixture over the frozen noodles. You don't need to stir, but do make sure the noodles are mostly submerged in the liquid.
Sprinkle the black pepper, onion powder, ground thyme, and salt on top.
Close the lid and set the vent to the sealed position. Select a 5 minute cook time at high pressure.
When the cook time is complete, allow a 15-minute natural release, followed by a quick release of remaining pressure.
After the pressure has released and the valve has dropped, carefully open the lid. Remove the chicken breast pieces to a cutting board.
Add the frozen vegetables to the pot, if using, and replace the lid, allowing the vegetables to heat through.
Shred or chop the chicken as desired and return to the pot. Add more salt and pepper to taste, if needed.
Let cool for about 10-15 minutes to allow the liquid to thicken, so it's more saucy and less soupy. Then serve and enjoy!