In a heavy bottom, pot add in the evaporated milk.
On a slow stovetop, let the milk come to a boil.
Once boiled let it cool down slightly. (around 8-10 minutes)
After 8-10 minutes add in the powdered jaggery and mix it until the jaggery is dissolved.
The temperature of the milk will reduce further.
Once you have achieved a lukewarm temperature, i.e. around 48 Deg C add in the yogurt.
I generally check it simply by dipping a clean finger. If able to touch it I add the yogurt. I have added the temperature here, for my readers who are unable to do so.
Add in the cardamom powder if using, and slightly mix.
Mix the yogurt culture in the milk using a whisk until it is all mixed.
Now pour the mixture in individual pots or 1 single pot as you prefer.
Cover with a plate or an aluminum foil.
If setting, without Instant Pot, Let it sit in a warm place undisturbed for 8-10 hours or best overnight.