In a large bowl or large zip-top bag, combine chicken, cornstarch, salt, and black pepper until well-coated. Set aside.
Press MANUAL or PRESSURE COOK (high) and set for 3 minutes. Once the 3 minutes is up and the Instant Pot beeps, allow to naturally release for 15-20 minutes. Open the lid and press the SAUTE button. Toss in the dried red chili peppers or red pepper chili flakes. Combine the cornstarch with water and stir into the Instant Pot. Cook and allow the sauce to bubble and thicken up.
If you want this dish saucier, feel free to double the amount of sauce and save the rest for another recipe.