If you're going for the dump and start method, then add all of the ingredients to the pot (except for the cornstarch) and skip to step 5. If you decide to do the saute steps, then in a bowl, mix the chicken with cornstarch until it's well coated.
On the Instant Pot press on SAUTE (on low) and heat the oil. Add the chicken, and brown it until lightly browned. Remove the chicken from the pot onto a plate and set aside. Work in batches.
Deglaze the pot by adding ¼ cup of water, and with a wooden spoon or a heat resistant spatula scrape off any bits stuck to the bottom of the pot. I recommend discarding the liquid and the chicken cornstarch bits that were stuck to the pot to get a smooth sauce.
On the SAUTE setting, cook the garlic, ginger, and chili flakes for 30 seconds. Then add 1 cup of the General Tso's Sauce, put the chicken back in and give everything a mix.
Secure the lid and set the vent to SEALING. Select the PRESSURE COOK/MANUAL setting and set the cooking time for 4 minutes at high pressure. The Instant Pot will take around 4 minutes to come to pressure and start cooking. When the cooking program ends, quickly release the steam and carefully remove the lid.
To Thicken the Sauce
Immediately after removing the lid, add the cornstarch mixed with water (just mix 1 tablespoon of cornstarch with 1 tablespoon of water - add more if needed). Whisk until the sauce is thickened (it thickens very quickly).If the sauce is no longer hot, just press the SAUTE button so it simmers gently as you thicken it (not boiling).
Serve over rice, and garnish with toasted sesame seeds and chopped green onion.
If you don't have fresh ginger available, you can substitute it with ground ginger (½ teaspoon of ground ginger).
This dish is mild-spicy, feel free to omit the chili flakes if you don't like any heat (I strongly recommend that you add them though).
It's important that you deglaze the pot after the saute to avoid getting a BURN message.
The reason why I like to deglaze and discard the liquid with the stuck bits then wipe the pot clean is to get a smooth sauce.
Serve over jasmine rice, and garnish with toasted sesame seeds and chopped green onions.
Store in the fridge in an airtight container for up to 3 days.
Freeze in a freezer-safe container for up to 3 months.