Pat chicken breasts dry with paper towels. Cut into a total of 6 evenly-sized pieces.
Add all of the ingredients to the pressure cooker pot, and briefly stir everything together.
Secure and seal the lid. Cook at high pressure for 10 minutes, then manually release the pressure by gradually turning the release knob to its venting position.
Uncover. Transfer the chicken pieces to a large plate and shred the meat using 2 forks (or shred directly in the pot). Transfer the shredded chicken back to the pot, and stir everything together to let the meat soak up the sauce.
Optional For Thicker Stew: Turn on the saute setting to medium heat. Boil until the liquid thickens to your desired consistency, 5 to 10 minutes, stirring frequently. Turn off the saute setting, and serve while hot.