Add the chicken in batches, setting on a plate once browned.
Put 1/2 cup of water in the Instant Pot, scrape the sides and bottom and turn it off.
Pour in the sauce from the medium bag and add the chicken back.
Lock the cover and seal the steam nozzle.
Set it to high pressure and cook for 5 minutes with a 10-minute natural release.
The sauce will be a bit runny. In a small bowl, mix together 1 Tbsp. of water with 1 Tbsp. of cornstarch and stir into the sauce. If desired, sprinkle with parsley or cilantro. Serve with Naan bread or over Basmati rice.