Wash the rice: place it in a large bowl of water and steep for at least 3 hours. Rinse several times and drain well.
Place the rice in a saucepan, cover with water and bring to the boil. Simmer gently for around 12 minutes.
Peel the bananas and slice into rounds.
Place the coconut milk, caster sugar and vanilla extract in a large saucepan. Heat gently for 5 minutes then add the banana slices. Continue cooking for a further 10 minutes.
Leave to cool, then serve with the hot rice.