Spray the inside of the Instant Pot with non stick cooking spray. Cut the chicken into bite sized pieces, dice the onion, and mince the garlic.
Turn the Instant Pot to "Saute", and add half of the oil. When hot, add half of the cubed chicken and cook just until browned. Remove and repeat with the remaining chicken.
Add all of the chicken pieces to the pot and add the salt, pepper, onion, garlic, soy sauce, ketchup, honey, and red pepper flakes. Use a metal spatula to scrape any browned bits off the bottom of the pot.
Secure the lid, and make sure the valve is set to seal. Set the instapot to "Manual/High" for 3 minutes.
When it’s done, use quick release to let out the steam. Remove the lid.
Set the instapot to SAUTE. Whis together the cornstarch and cold water until dissolved. Add to the sauce. Cook and stir until the sauce is thick and bubbly.
Serve over rice. Garnish with sesame seeds and sliced green onions.
Notes
-You can brown the chicken in a skillet and then transfer it to the Instant Pot. There's another dish to wash, but it can be cooked all in one batch.