Wash the rice, then soak for 30 minutes in cold water. Drain well. Remove the seeds from the cardamom pods and lightly crush them in a spice grinder or pestle and mortar.
Bring the milk to the boil in a large heavy-based saucepan and add the rice and cardamom. Reduce the heat and simmer for 1½-2 hours, or until the rice has a creamy consistency. Stir occasionally to stop the rice sticki