Preheat the air fryer to 400°F (200°C) for about 5 minutes.
Cut chicken thighs into bite-sized pieces.
Place chicken in a bowl and add cornstarch, salt, and black pepper.
Toss until the chicken is evenly coated.
Spray the air fryer basket with cooking spray.
Arrange chicken pieces in a single layer in the basket.
Air fry for 10–12 minutes, shaking the basket halfway through.
While the chicken cooks, prepare the sauce.
In a small saucepan, combine ketchup, soy sauce, brown sugar, garlic, ginger, and red pepper flakes.
Simmer the sauce for about 3–4 minutes until slightly thickened.
Remove the chicken from the air fryer once crispy and fully cooked.
Toss the chicken pieces in the warm General Tso’s sauce.
Serve immediately over cooked rice.
Garnish with sesame seeds and sliced green onions.