Peel the mangoes and roughly chop the flesh (reserve a little for garnish). Process into puree in a blender, place in a bowl and set aside.
Bring the milk to the boil in a large saucepan, reduce the temperature, simmer. Add the rice and simmer for about 25 minutes, stirring, until the rice is soft. Remove from heat, add sugar and stir until sugar has dissolved. Let cool down. Add the mango puree and other ingredients, pour into glasses and cool.