Keep the yogurt in a muslin cloth over a seive into a bowl. Keep covered in the fridge to drain till use.
Heat milk in a thick bottomed saucepan. Once boiled, keep it on simmer and allow it to cook till it reduces to half. Scrape the sides to push back the cream in.
Half way, crush in the saffron and cardamom.
Once the milk is half and looks thick, add the sugar and salt and cook for a couple of minutes.
Switch off, allow it to come to room temperature.
Keep chilled in the refrigerator till cold.
Bring out the hung curd and the milk. Drop the curd in and give it a good whisk to make the mixture creamy.
Pour into two glasses, top with saffron and crushed pistachios.
Serve immediately.
Notes
I have used double cream milk to give it a thicker texture, you can use full fat milk and boil it till half and thick