In a bowl, add the chicken cubes along with soy sauce, dark soy sauce, oyster sauce, sweet chilli sauce, garlic powder, paprika, black pepper, and MSG.
Mix well until the chicken is evenly coated.
Cover and marinate for at least 30 minutes, or up to overnight in the fridge for deeper flavor.
Thread the marinated chicken pieces onto skewers, leaving a little space between each piece so they cook evenly.
Preheat the oven to 180°C (fan).
Arrange the skewers on a baking tray or wire rack placed over a tray (this helps the chicken cook evenly).
Bake for 10–15 minutes, flipping halfway, until the chicken is cooked through and lightly caramelized.
In a small bowl, whisk together mayonnaise, sweet chilli sauce, lime juice, salt, and pepper until smooth and creamy.
Taste and adjust seasoning if needed.
Serve the hot chicken skewers over steamed rice and drizzle generously with the bang bang sauce.
You can also serve extra sauce on the side for dipping.