Melt the ghee in a saucepan and, when hot, add the onion. Cook for 8–10 minutes, then add the garlic, ginger and chilli and cook for 2 minutes.
Stir in the spices and cook for 1 minute. Add the tomato and juices, tomato paste and coconut milk. Bring to below boiling point and simmer for 10 minutes. Add the prawns and cook for 3–5 minutes. Season w