Pat the chicken pieces very dry with paper towels. Season with salt and pepper in a large mixing bowl.

In a separate shallow dish, whisk together the cornstarch and flour.

In another shallow dish, whisk the egg.

Dip each chicken piece first into the whisked egg, letting excess drip off, then dredge thoroughly in the cornstarch-flour mixture, pressing to coat evenly. Place coated chicken on a plate, ensuring pieces aren't touching to prevent sticking.

Preheat your air fryer to 375°F (190°C) for 5 minutes.

Lightly spray the air fryer basket with cooking oil.

Place coated chicken pieces in a single layer in the air fryer basket, ensuring not to overcrowd. You will likely need to cook in 2-3 batches. Lightly spray the chicken with cooking oil.

Air fry for 10-12 minutes, flipping halfway through, until golden brown and cooked through (internal temperature reaches 165°F / 74°C). Repeat with remaining chicken.

While the chicken is air frying, whisk together the chicken broth, soy sauce, sugar, rice vinegar, sesame oil, cornstarch, minced garlic, and grated ginger in a small saucepan.

Bring the mixture to a simmer over medium heat, whisking constantly, until the sauce thickens to your desired consistency (about 3-5 minutes). Remove from heat.

Once all chicken is cooked, transfer the crispy chicken to a large mixing bowl.

Pour the warm sesame sauce over the chicken and toss gently until all pieces are evenly coated.

Serve immediately, garnished with toasted sesame seeds and sliced green onions. Delicious with steamed rice and stir-fried vegetables.