In a bowl, mix together the cornstarch and flour. In a separate bowl, whisk the egg, soy sauce, black pepper, garlic powder, and onion powder. Dip each slice of beef into the egg mixture, then coat it thoroughly with the cornstarch-flour mixture.

Preheat the air fryer to 400°F (200°C) for 5 minutes. Lightly spray the air fryer basket with oil to prevent sticking. Arrange the beef slices in a single layer, cooking in batches if needed to avoid overcrowding. Air fry at 400°F (200°C) for 6-8 minutes, flipping halfway through, until the beef is crispy and golden brown.

In a saucepan, combine the soy sauce, hoisin sauce, rice vinegar, brown sugar, chili garlic sauce, minced garlic, and minced ginger. Bring the mixture to a simmer over medium heat, stirring frequently, and cook for about 5-7 minutes until the sauce thickens slightly.

Toss the crispy beef in the prepared sauce until evenly coated. Serve immediately, garnished with sliced green onions and sesame seeds for a fresh, flavorful finish.