Sprinkle the chicken with cornstarch, salt, pepper, and garlic powder. Gently massage the cornstarch and seasoning into the chicken, ensuring each piece of chicken is evenly coated. Set aside.
Next, mix the dark soy sauce, water, oyster sauce, sake, chili paste, and ketchup together in a small bowl. Set aside.
Heat the vegetable oil in a large stainless steel wok or skillet set over high heat. Add the coated chicken pieces and fry until golden brown and cooked through then remove the chicken to a clean plate. Set aside.
Reduce heat to medium-high heat. Add the whole red chilies, broccoli florets, and carrots to the same stainless steel wok or skillet. Sauté for a minute or so, stirring frequently, then add the green and red bell peppers and cook for an additional 2 minutes.
Stir in the baby corn, peanuts, ginger, and garlic and cook for 1 minute or until the garlic becomes fragrant.
Pour the Hunan sauce over the vegetables and cook for 3-4 minutes or until the sauce starts to simmer. Add the chicken back to the skillet and toss well to coat with the sauce.
Stir and cook for an additional 2 minutes or until the sauce thickens.
Serve over cooked rice and garnish with freshly chopped green onions if desired.