Select the “Sauté” function on the Instant Pot and heat up the olive oil.
Add diced onion and prepared peppers to the hot oil; cook for 2 minutes.
Stir in chicken pieces and garlic; season with curry, basil, ginger salt, chili powder, cayenne, pepper, and white pepper.
Cook and stir until chicken is just browned, about 2 minutes. Stir in the tomato paste until incorporated.
Add coconut milk to the pot, and scrape up the browned bits from the bottom of the pot using a wooden spoon.
Turn Off the Instant Pot. Secure the lid and make sure the vent is closed.
Select Manual (or Pressure Cook) and set it to cook for 5 minutes.
When time is up, do a quick release. When the pin drops, remove the lid.
Carefully remove 1/4 cup of the liquid from the pot and transfer it to a small bowl; whisk the cornstarch into the liquid until thoroughly combined.
Whisk the cornstarch mixture (slurry) back into the Instant Pot; mix and stir around until incorporated and sauce is thickened.
Serve Coconut Curry Chicken over rice and garnish with cilantro.