Heat half the oil in a saucepan and stir-fry the rice until all the grains are glossy. Add the cumin seeds, cinnamon stick, lime leaves, coconut milk, water and salt. Bring to the boil and simmer gently over a low heat for 10 minutes. Remove from the heat, cover and leave to rest for 10 minutes.
Meanwhile, heat the remaining oil in a wok and stir-fry the garlic, ginger and crushed dried chillies for 30 seconds. Add the prawns and stir-fry for a further 3–4 minutes, until pink.
Stir in the coconut rice with the fish sauce, lime juice and coriander. Serve scattered with the peanuts.