Switch the pot to Saute mode. Melt a stick of butter in the pot until it becomes foamy.
Toss in onions and garlic and cook until they are about halfway done.
Add the frozen or raw chicken to the pot. Cover it with the sauce.
Cover the pot, select the meat setting. Cook for 10 minutes with 10 min NPR. *Natural Pressure Release.
If after 10 minutes the lid has not unlocked, release the excess steam and remove the lid.
Shred or cut the chicken. I like to remove the chicken and use two forks to shred it.
Add the shredded chicken back to the pot and let it simmer in the sauce for a few minutes.