Creating Crispy Chilli Chicken is straightforward. Follow these steps:

1. Prepare Chicken: In a bowl, mix cornstarch, salt, black pepper, garlic powder, and ginger powder. Add the chopped chicken and mix until fully coated.
2. Beat Egg: In another bowl, beat the egg and then add it to the cornstarch-coated chicken. Mix well until all pieces are coated.
3. Heat Oil: In a large frying pan, heat enough oil for deep frying over medium heat.
4. Fry Chicken: Carefully add the coated chicken pieces to the hot oil in batches. Fry until golden brown and crispy, about 5-7 minutes. Drain on paper towels.
5. Prepare Sauce: In a separate pan, heat 3 tablespoons of vegetable oil. Add dried red chilies, minced garlic, and minced ginger. Sauté until fragrant.
6. Add Vegetables: Toss in the chopped onions and bell peppers. Stir fry for 2-3 minutes until they begin to soften.
7. Combine Sauces: In a bowl, mix soy sauce, chili sauce, vinegar, sugar, and sesame oil. Pour this mixture into the pan with the vegetables.
8. Finalize the Dish: Add the fried chicken pieces to the pan, tossing them in the sauce to ensure they are evenly coated. Cook for another 2-3 minutes.
9. Garnish: Remove from heat and garnish with chopped spring onions.
10. Serve Immediately: For the best flavor and texture, serve your Crispy Chilli Chicken immediately.