Season chicken with salt and pepper. Set pressure cooker to "sear" and add oil. Press "start/stop". When hot, add chicken and brown. Add onions and garlic and cook for an additional 3 minutes. Add soy sauce, ketchup, and pepper flakes. Stir.
Close and lock lid and set pressure cooker to "poultry". Adjust time to 8 minutes and press "start/stop". When done, quick release and make sure all pressure is released before opening lid. Carefully open lid and add sesame oil and honey. Stir.
In a mixing bowl, combine water and cornstarch. Pour mixture into cooker and stir to thicken sauce. Set pressure cooker to "sear" and
adjust time to 10 minutes. Press "start/stop" and bring to a simmer. Add cornstarch/water mixture and stir to thicken sauce. Check seasoning and add salt and pepper, if needed.
Once sauce has reached desired consistency, plate, and garnish with scallions and sesame seeds. Serve with rice.
