Soak saffron in 1tbsp milk and keep aside
Soak pistachio for few hours and then peel and slice them.(you can also dry grind them coarsely without soaking)
In a wide and heavy bottom pan boil milk and let it simmer till it reduce to 3/4 in quantity.
Now add grated mawa ,saffron, chopped pistachio and sugar and let it cook for 5 minutes.
Meanwhile keep stirring to mix the mawa ,there should not be any lumps left.
Now remove from the heat and add cardamom powder.
Let it cool down at room temperature then add the kewra essence(or rose water)
Now fill it in the kulfi moulds till 3/4 volume and keep in the freezer to set.
When you want to serve then just wash the mould with tapid water or rub between your palms or just slide a butter knife around it.
Serve immediately .