Put milk in a heavy bottom wok/ kadai or a saucepan and bring it to a boil.
Remove about 2 tbsp of the hot milk and add to a small bowl. Add the saffron to it. Allow the saffron to infuse into the milk.
Lower the heat and let the milk simmer till it becomes half the quantity. In between don't forget to stir the milk so that it does not stick to the bottom of the pan. Also keep scraping the milk solid that develops on the sides of the pan and add to the milk.
This will take about 10 -15 minutes in a kadai. It will take longer if you are using a saucepan.
While the milk is simmering, process the almonds and pistachios into a coarse powder. You can use a mortar and pestle, chop it up roughly using a sharp knife or use a food processor.¼
Add grated khoya and sugar to the reduced milk. Mix well.
At this point you will find that the mixture becomes more liquid. Don't worry it will become thick as you allow it to simmer for further 10 -15 minutes.
By now you should have a thick custard like mixture.
Add the coarsely chopped nuts, saffron milk, nutmeg and cardamom powders to the mixture.
Mix well. Allow the mixture to cool down a bit, especially if you are going to use metal moulds.
Spoon the mixture into the moulds.
Put the moulds in the freezer.
The kulfi will freeze within 4-6 hours.
To serve, dip the mould in warm water. Run a knife along the edges and the kulfi will come out.
Slice it up and serve.