Bring the milk to the boil in a large saucepan, stirring. Reduce the temperature and simmer the milk gently for 20 min.
Add the long grain rice and sugar and simmer on low heat for another 35-40 min until the milk is completely thickened and, if the recipe is prepared for 4 people, reduced to 1, 1 liter. Keep stirring so that the milk does not burn.
Add the raisins and cardamom and simmer gently, stirring, for another 3-4 minutes. Remove the saucepan from the stove.
Sprinkle the pudding with pistachios and serve hot or cooled.