Add all ingredients to pressure cooker except cornstarch mixture and scallions.
Close and lock lid, set pressure cooker to "poultry", adjust time to 25 minutes, and press "start/stop".
When done, quick release and make sure all pressure is released before opening lid.
Carefully open lid and remove chicken to serving platter to rest.
Skim off fat from liquid left in pot. Set cooker to "sear", adjust time to 10 minutes, and press "start/stop". Bring sauce to a simmer then
add cornstarch mixture. Stir and mix well.
Simmer until sauce reaches desired consistency. Ladle over chicken on serving platter. Garnish with scallions. Serve hot.