In a large bowl, combine chicken thighs, egg, soy sauce, garlic powder, onion powder, ginger powder, paprika, and cayenne pepper. Ensure the chicken is well-coated and fully immersed in the marinade. Cover and let rest for at least 30 minutes.

While the chicken marinates, whisk together the sauce ingredients in a medium bowl: Asian chili sauce, soy sauce, oyster sauce, ketchup, honey, and Chinkiang vinegar. Mix until smooth and set aside.

In a large resealable plastic bag, combine flour, cornstarch, and a pinch of garlic powder. Remove the chicken from the marinade, allowing excess egg to drip off. Place in the bag, seal it, and shake until well-coated.

Heat a generous amount of oil in a nonstick skillet over medium-high heat. Add the breaded chicken in batches, cooking for about 4 minutes on each side or until golden brown and crispy. Transfer to a plate lined with paper towels.

In a separate dry skillet, toast unsalted cashews over medium heat for 3-4 minutes, or until golden and fragrant. Remove and set aside.

In the same skillet, heat a drizzle of oil. Add sliced onion and red bell pepper, stir-fry for about 2 minutes until tender-crisp. Incorporate minced garlic and fresh ginger, stir-frying for another 30 seconds.

Pour the prepared sauce into the skillet with sautéed vegetables, stirring constantly until it comes to a gentle simmer, cooking for about 1 minute until thickened.

Toss the cooked chicken and toasted cashews into the skillet, stirring until everything is beautifully coated. Garnish with sesame seeds and chopped green onions. Serve immediately.