In a medium bowl mix all the ingredients mentioned under Teriyaki sauce.
Add the chicken to the sauce and stir to coat.
Set the instant pot on SAUTE function, Add ½ cup of chicken stock.
Add the chicken and all the marinade, and spread the pieces evenly.
Select the PRESSURE COOK button on HIGH PRESSURE for 10 minutes. (Make sure the valve is in the SEALING position).
Once the pressure-cooking cycle is over, allow the pressure to release naturally for 5 minutes then quick release pressure by manually moving the valve from the SEALING to the VENTING position.
Open the lid carefully and select the CANCEL button.
Combine cornstarch and water.
Select the SAUTE button and stir in the flour mixture and let it simmer for 3 minutes. Until the sauce thickens. Finish with adding a teaspoon of butter (for shine and smoothness).
Once done CANCEL the SAUTE button.
Serve with Rice and broccoli, sprinkled with sesame seeds and chopped green onions.