Method

1. Preheat the oven to 180C/350F/Gas 4.

2. Remove the heads from the prawns and place them in a pan with 150ml/5fl oz of boiling water. Simmer for five minutes, mashing the heads into the water to extract their flavour. Strain through a sieve into a clean ovenproof pan.

3. Add the onion, pak choi, rice, stock cube and chilli to the pan. Pour in a little more boiling water to just cover the ingredients in the pan. Cover with a lid and place in the oven to cook for about ten minutes.

4. Take the pan out of the oven and stir in the prawns, and then return the pan to the oven for a further five minutes, or until the prawns are pink and cooked through.

5. Remove the pan from the oven and stir in the mango, fluffing up the grains of rice with a fork.

6. Serve in a bowl, garnished with a lime half.