Wash and soak basmati rice for 10 - 15 mins. Meanwhile boil the milk in a thick bottom pan. Once it reaches the boiling point, reduce to low flame and stir occasionally.
Soak saffron in a quarter cup of warm milk.
Heat a pan with ghee, roast the nuts till golden, remove and keep aside. Then drain the rice and roast for a minute. Remove from flame.
Add the roasted rice to the boiling milk and simmer for 20 mins. Check in interval to see if the grains are cooked. This can be done, by pressing a grain between your fingers. Reduce further for 5 mins. Add sugar and stir well to mix it.
It takes about 30 - 40 mins for the milk to get reduced to thick consistency. At this stage add the condensed milk, saffron milk and cardamom powder. Stir well, have the flame still in low. When it is mixed well, bring to boil on high flame, add in the roasted nuts, simmer for 5 mins.
This tastes great both hot or cold.