Blend the mangoes into a smooth puree.
In a saucepan, combine the milk, sugar, and rice flour. Cook over medium heat, stirring constantly, until the mixture thickens.
Remove the saucepan from the heat and stir in the mango puree and crushed cardamom pods.
Pour the mango phirni into individual serving bowls and chill in the refrigerator for at least 2 hours before serving.
