Mix tamarind paste, palm sugar, soy sauce, garlic, ginger, and chili flakes to make a marinade. Coat the lamb well and let it marinate for at least 2 hours, preferably overnight for deeper flavor. Preheat the oven to 160°C, place the lamb in a tray, cover with foil, and bake for 2 hours until tender. Remove the foil, brush with extra marinade, and bake uncovered for another 20 minutes until caramelized. Serve hot with coleslaw and chips for a delicious Aussie BBQ-style dish.
