Start by cutting the chicken thighs into 2-3 inch chunks. I tend to leave them a bit larger as the pressure cooker tends to make the chicken very moist, which helps to avoid breaking the pieces.
Heat up your pressure cooker: press Sauté, click on the Adjust button, and select More to activate the Sauté More function. This means that the food will be sautéed over medium-high heat. Wait for the Instant Pot indicator to read HOT.
Add the oil to the hot IP, wait one minute for the oil to heat up, and add the chicken. Sauté for 2-3 minutes, stirring a few times, until it just starts to get golden.
Add the remaining ingredients to the pot: ginger, garlic, red pepper flakes, hoisin sauce, soy sauce, rice vinegar, brown sugar, and water. Stir well to combine.
Close the lid, select the Poultry function, and adjust the time to 5 minutes.
Use a 10-minute Natural Release. Turn off the heat. Release the remaining pressure. Open the lid. Gently stir, being careful not to crush the chicken.
Select the Sauté function again. In a small bowl, combine the cornstarch with the water and whisk until all is combined with no lumps. Add the mixture to the Instant Pot and gently stir to combine. Cook on Sauté function for five more minutes, stirring occasionally, until the sauce thickens.
Turn off the Instant Pot and let the Instant Pot General Tso Chicken stand for 5-7 minutes; the sauce will thicken more.
Serve over rice with broccoli and garnish with fresh chopped green onions, red pepper flakes, and sesame seeds.