Roast sesame seeds in a wide frying pan over low heat till the begin to pop and you get the aroma of roasted sesame seeds.
Remove the seeds from the pan into a tray or plate. Allow the seeds to cool a bit.
Keep a glass of water ready.
Also lightly grease a baking tray upside down, or grease your worktop. Or better still use a silicon mat. I prefer using the mat as you don't need to grease it. Grease a rolling pin lightly and keep it ready.
In a heavy based pan, add jaggery. Put the pan on medium to low heat.
Keep stirring the jaggery till it melts. Allow the jaggery to cook till it begins to bubble at the sides.
Add a few drops of the melted jaggery in a glass of water. It should form a soft ball. This means that the jaggery is ready.
Add ghee and mix well. The mixture will become frothy and begin to bubble.
Add cardamom powder and mix well. Immediately add the roasted sesame seeds.
Mix well.
Immediately add the sesame mixture and mix well. Take the pan off the heat.
Immediately put the mixture onto the prepared tray, worktop or the silicon mat. Using the spatula spread out quickly.
Roll the mixture out as thin as possible.
Immediately cut the chikki into squares or diamonds, using a sharp knife or a steel spatula.
Allow the chikki or brittle to cool down for 10-15 minutes.
Store the tal sankari or chikki in an airtight container.