Combine besan, ghee, sugar, milk and the nuts mixture in a wide nonstick pan. Cook on medium flame, mixing frequently. Sugar will melt and the mixture will get liquidy initially and starts to thicken as it cooks.
Once the mixture starts to thicken, then stir continuously until the mixture starts to leave the sides of the pan. The whole process takes about 25-30 minutes depending on the quantity of ingredients you are making.
Add ground cardamom and mix well.
Pour the mixture on the greased plate and spread into an even layer with the back of a wide spoon. Let cool before cutting into diamonds or squares.
These store well in an airtight container for up to 7-10 days.