In a heavy bottomed medium size saucepan on medium heat, bring the milk to a boil, stirring occasionally, to avoid burning the bottom.
Lower the heat to medium-low and simmer the milk until thick and creamy, stirring occasionally to avoid scorching. Around the 30 minute mark, stir in the condensed milk. Continue to simmer until the milk thickens and reduces to about half of the original volume, takes about 45 minutes to 55 minutes.
Add saffron and ground cardamom to the milk mixture in the last 10 minutes of cooking. Mix well. Remove from heat and cool completely.
Chill in the fridge for at least 3~4 hours.
When ready to serve, puree 1 mango and mix with the kheer. Chop the other mango and garnish the serving dishes with cubed mango for a double dose of mango goodness.