Place the chicken in the pot. One layer, if possible.
Mix together the water and chicken bouillon. Pour over the chicken.
Sprinkle the salt, pepper, onion powder, and garlic powder.
Turn the chicken breasts over a couple times to coat both sides of the chicken.
Close the lid and set the steam release knob to the Sealing position, if not self-sealing.
Press the Pressure Cook/Manual button or dial, then the +/- button or dial to select 12 minutes (add about 4 minutes for frozen, depending on the size. High Pressure. The pot will take a few minutes to come to pressure.
When the cook cycle has finished, turn off the pot and let it sit undisturbed for 5 minutes (5 minute natural release). Then turn the steam release knob to the Venting position to release the remaining steam/pressure.
When the pin in the lid drops back down, open the lid.
Let the chicken rest a few minutes before shredding. Save the broth from the pot.
Then use 2 forks to shred the meat, or use a stand mixer with the paddle attachment, or a use hand mixer to shred the meat.
Add about ⅓ cup of the broth to the shredded chicken to flavor it and keep it moist. Use more, if needed.
Store the remainder of the broth for soup or other recipe, if you want.
Store the shredded chicken breast meat in a storage baggie, or other airtight container and keep in the fridge for up to 5 days. To freeze the chicken meat, put in a freezer baggie or freezer-safe container and freeze up to 3 months.