Heat a wok over high heat. Add the shrimp paste, cinnamon stick and star anise. Stir-fry for 30 seconds or until aromatic. Add the curry paste and turmeric. Stir-fry for a further 30 seconds or until aromatic. Add the coconut cream, lemongrass and half the curry leaves. Reduce heat to medium and simmer, stirring occasionally, for 7 minutes or until thickened slightly.
Add the chicken, tamarind and sugar to the wok. Cook, stirring occasionally, for 3 minutes or until the chicken is cooked through. Top with the remaining curry leaves and serve with the roti.