Peel the mangoes and slice the flesh into a blender (reserving a little for the garnish).
Blend to a puree, transfer to a bowl and set aside.
Bring the milk to the boil in a large pan, and then reduce to a simmer.
Pour in the rice. Cook, stirring regularly, for about 25 minutes, or till the rice is soft.
Turn off the heat, add the sugar and stir until dissolved.
Set aside to cool and, once tepid, stir in the mango puree and the remaining ingredients.
Pour into decorative glasses and chill until ready to serve.
Serve the kheer garnished with chopped fresh mango and slivers of chopped pistachio.