In a small bowl, whisk all sauce ingredients except PB2 and peanut butter (they will burn if you put them in before cooking). Pour 1/2 of the sauce into the bottom of the Instant Pot. Add chicken, then add remaining sauce.
Set Instant Pot to high pressure for 12-14 minutes (do 14 mins for thicker pieces of chicken), followed by manual release. Remove chicken, shred, and set aside. Pour the sauce into a bowl and whisk in PB2 and peanut butter.
Set Instant Pot to sauté and add bell pepper and broccoli slaw. Sauté for 5 minutes or until pepper begins to soften slightly. Return sauce to the Instant Pot and mix.
Return chicken to mixture and stir to coat. Add a little chicken stock if the sauce is too thick.
Serve chicken mixture over a bed of rice and top with fresh cilantro, green onions, and peanuts (if desired).