Line a small 8 inch by 8 inch square dish with baking paper.
Grate paneer. Set aside.
Heat ghee in a large frying pan over medium-low heat.
Add paneer. Sauté, stirring, for about 1-2 minutes or until lightly toasted.
Add condensed milk. Cook, stirring, for about 6-7 minutes or until the mixture is very thick.
Add ground cardamom. Stir to combine.
Remove from heat.
Transfer the mixture to the prepared dish. Use a spatula to spread it evenly.
Sprinkle with chopped nuts. This is totally optional.
Allow kalakand to completely set at room temperature. This will take about 2 to 4 hours.
Remove kalakand from the dish.
Cut into small squares as desired.
Serve immediately or store in an airtight container in the refrigerator for about 2-3 days.