Use a pestle and mortar or a food processor to crush all the herbs and spices, including lemongrass, cilantro root, palm sugar (if you're using solid palm sugar), garlic, and white peppercorns.
Combine the mixture mentioned above with fish sauce, soy sauce, dark soy sauce and water. Mix everything thoroughly with the chicken. Finally, add some cooking oil. Mix well.
Grill the chicken:
Before cooking the chicken, allow it to sit at room temperature for 30 minutes.
When using an air fryer, start by placing the chicken upside down in the air fryer and cooking it for 15 minutes at 356°F (180°C). Afterward, raise the temperature to 400°F (200°C), flip the chicken, and air fry for an additional 5 minutes or until golden brown.
When using the oven, preheat it to 400°F (200°C) for 15 minutes. Put the chicken on a grill rack with the drip tray below and bake for 15-20 minutes or until golden brown.
Enjoy the grilled chicken:
Enjoy Ping Gai / Kai Yang with sticky rice like a typical Thai / Lao.