Pour the milk in a deep heavy bottom pan and start boiling it on low heat. When the cream starts forming on the milk, stir and mix it in the milk. Occasionally (every 5 minutes) stir the milk in the pan. If the cream sticks to the sides, gently scrape it from the sides and mix it with the milk in pan.
You will need a deep bottomed pan because the milk must be boiled till it reduces to half of the original quantity.
When the boiling process is going on de-shell the pistachios. Slice the cashewnuts, almonds and pistas.
Microwave the pistas, cashewnuts and almonds slivers in 1/4 cup water for 30 seconds. Let it cool.
You can even soak the dry fruits in hot water for 15 minutes.
Soak the saffron strands in 2 tablespoon milk so that the saffron flavour gets infused in the milk.
Do not forget to stir the boiling milk every 4-5 minutes, while keeping the other ingredients ready.
Once the milk reduces to half the original quantity, mix sugar and stir.
Add the saffron infused milk to the boiling milk.
Now stir this continuously for another 10 minutes taking care that the milk does not stick to the bottom of the pan.
Let the rabdi cool down.