Stir the chicken into the bowl with the egg and add in the 3 tablespoon of cornstarch, ½ tsp pepper, and 3 tablespoon soy sauce. Coat well.
Set Instant Pot to SAUTE and wait for it to read, "HOT."
Pour in the 2 tablespoon of oil and add in bite-sized chicken pieces and mixture. (Complete this in 2 batches.)
Brown all sides of the chicken.
Press Cancel.
Deglaze pot by scraping the bottom of the pot until nothing is stuck to it.
Add in the Sauce Ingredients: ¼ cup of soy sauce, 2 tablespoon of sesame oil, 2 tablespoon of brown sugar, 1 tablespoon of rice vinegar, 1 ½ tsp ginger, 1 garlic clove, and the ¼ cup of water.
Close the lid on the Instant Pot and set it to MANUAL for 4 minutes.
Do a quick release (QR) and stir.
Sprinkle with toasted sesame seeds and garnish with green onions.