Cut chicken into 1-inch pieces, marinate with chicken bouillon powder, white pepper, and water for at least 10 minutes.
Combine light soy sauce, oyster sauce, rice vinegar, ketchup, honey, brown sugar, and water in a bowl to make the sauce.
Whisk together eggs, flour, cornstarch, baking powder, salt, water, and vegetable oil until smooth to make the batter.
Heat vegetable oil in a wok to 365°F (185°C) and fry the battered chicken pieces for about 3 minutes until golden brown.
Increase oil temperature to 375°F (190°C) and double fry chicken pieces for about 2 minutes until crispy.
Sauté minced garlic in the wok, add the sauce mixture, and simmer for 2 minutes. Thicken with cornstarch slurry.
Toss fried chicken pieces in the honey sesame sauce until evenly coated and garnish with green onions and sesame seeds before serving.