Make the spice paste: in a blender combine the peeled Shallots, Garlic, peeled Ginger, sliced Galangal, the white part of the Lemongrass (finely chopped), rehydrated Dried red chilies, chopped Fresh red chilies, a knob of Belacan (shrimp paste), Ground turmeric, a pinch of Salt and a few tablespoons of Water; blitz to a smooth paste.
Heat 2–3 tablespoons of Neutral cooking oil in a skillet over medium heat and fry the spice paste until it turns fragrant, the oil separates and the raw smell disappears, about 5–8 minutes.
Pour in the Thick coconut milk and stir to combine, then add the Tamarind paste (asam jawa) and Palm sugar (gula melaka); simmer gently, stirring often, until the sauce thickens slightly and the flavors meld—taste and season with more salt (if needed).
Prepare the Whole chicken by patting it dry and, if desired, spatchcocking it for even cooking; rub some of the warm spice paste under the skin and all over the bird, reserving the coconut-tamarind sauce for basting and serving. Allow to marinate for at least 1 hour or overnight in the refrigerator for best flavor.
Preheat your grill to medium or your oven to 200°C (400°F). If roasting, place the chicken on a rack over a baking tray; if grilling, set up for indirect heat. Roast or grill the chicken, basting generously every 8–10 minutes with the coconut-tamarind sauce so it builds up a glossy, caramelized coating.
Continue cooking until the chicken is cooked through (internal temperature 75°C / 165°F at the thickest part) and the skin is deeply colored and sticky, about 35–50 minutes depending on size and method; if the sauce is burning, reduce the heat and baste less frequently.
When cooked, rest the chicken 10 minutes to let the juices redistribute, then carve and spoon any remaining sauce over the slices before serving.
Optional: if you like a thicker glaze, reduce extra reserved sauce in a small pan over medium heat until noticeably syrupy and brush over the chicken just before serving.
