Heat 1 tbsp of vegetable oil in the Pressure Cooker, using the BROWN setting. Add the chicken and evenly brown all sides. Add onions and celery and cook for 1 minute. Place the rest of the ingredients.
Cover and lock lid. Turn the regulator knob to pressure and select HIGH cooking mode to cook for 10 minutes.
Release pressure by using the quick-release method. When the pressure has dropped, unlock and remove the lid.
If the chicken is not tender, cover and cook under pressure for an additional 10 minutes.