To begin, prepare the chicken by butterflying it (or use chicken thighs if preferred). Preheat your oven to 180°C (350°F) if you're planning to finish cooking the chicken in the oven. Set aside a large bowl to mix the marinade ingredients.

In a large bowl, mix together the minced garlic, chopped cilantro root, fish sauce, soy sauce, oyster sauce, lime juice, brown sugar, ground white pepper, and vegetable oil. Stir until the sugar has dissolved and the mixture is well combined. This marinade balances the salty, sweet, and umami flavors essential to Gai Yang.

Place the chicken in the bowl with the marinade, ensuring it is thoroughly coated on all sides. Use your hands to rub the marinade into the chicken, making sure to get the mixture under the skin for maximum flavour. Cover and refrigerate for at least 2 hours, or preferably overnight, to allow the chicken to absorb the flavours.

If grilling, preheat your grill to medium heat. Oil the grill grates lightly to prevent sticking. If using an oven, preheat it now to 180°C (350°F).

Place the chicken on the grill, skin-side down, and cook for 10-15 minutes, allowing the skin to develop a golden brown colour and slightly charred edges. Flip the chicken occasionally to ensure even cooking. If you’re using an oven, place the chicken skin-side up on a baking sheet.

If finishing in the oven, transfer the chicken from the grill to the preheated oven and bake for 20-25 minutes, until the internal temperature reaches 75°C (165°F). Alternatively, continue grilling the chicken on low heat for 30-40 minutes, turning frequently to prevent burning.

Once fully cooked, remove the chicken from the grill or oven and let it rest for 5-10 minutes before cutting. This resting time ensures the juices are reabsorbed into the meat, keeping it tender and flavourful.

To serve, slice the grilled chicken into pieces and present it with sticky rice and fresh herbs like cilantro or mint. For an authentic touch, pair the Gai Yang with Nam Jim Jaew, a spicy dipping sauce that complements the smoky, grilled flavors. The balance of tangy, sweet, and spicy enhances the richness of the grilled chicken.