Add ketchup, brown sugar, pineapple, soy sauce, lime juice, and garlic to the instant pot. Mix well.
Add the chicken thighs to the pot.
Put the lid on and set to manual high pressure for 12 minutes (10 minutes if using fresh chicken). Don't forget to seal the steam valve.
When it is done cooking, do a Natural Pressure Release (NPR) for at least ten minutes. Then do a quick release.
Remove chicken from pot. You can leave whole or shred. Let the juices stay in the pot to thicken.
Add the cornstarch to the water and mix well. Add to the pot.
Turn the “Sauté” function on, and mix the cornstarch mixture into the sauce. Let simmer while stirring often until thickened. About 5-10 minutes.
Pour sauce over chicken and serve with rice. Garnish with green onions and sesame seeds.
