Put the rice on to cook in a pan of lightly salted boiling water and leave to cook for about 12 minutes.
Meanwhile, start the curry. Melt the butter in a large saucepan and gently fry the onion for 4-5 minutes, until soft and golden. Add the garlic, ginger, mango, cardamom and cinnamon stick and cook gently for another 2-3 minutes. Stir in the turmeric and chilli powder, then add the prawns and Rubicon Mango Drink. Simmer for 5 minutes.
When the rice is almost cooked, melt the butter in a large frying pan and add the cumin seeds, cloves and bay leaves. Fry gently for 2-3 minutes.
Drain the rice thoroughly and add it to the frying pan, stirring to coat in the spice mixture. Season the prawns with a little salt and stir in the coriander.