Grease a platform with ghee to begin with. You can also grease a rolling pin or use a butter paper for rolling without sticking.
After that, take a pan and start roasting it in medium heat.
It will start to pop after a minute or so. Keep stirring constantly for even roasting.
Once you see golden sesame seeds here and there you can transfer to a plate for cool down. Make sure all are roasted well (stir well to ensure this)
Then in the same kadai, add jaggery powder, water.
Continue by stirring to dissolve the jaggery. Keep the flame only in low.
Keep a bowl of water in the side to check syrup consistency. When it starts to boil and becomes frothy, add ghee and mix.
Add couple of drops to the water and check.
First, it will be soft. Then you will be able to take out the string but it bends.
Continue heating and checking. The correct stage is when you pour a little syrup in water, it should harden and you should be able to take out. It should break crisp. This is what we are looking for.
Beyond this, the syrup will get burnt, so be careful while checking, you can even switch off the flame while checking.
Add cooking soda and mix briskly. In low heat itself, add sesame seeds and mix quickly.
When all the seeds mix and forms a mass switch off and transfer the mixture immediately to greased platform.
Put the butter paper over it and roll it using rolling pin. Do it gently first to spread out and then press swiftly to roll out thin.
Make impressions using knife (no need to cut and take out) as desired.
It gets cooled so fast, so you have to act quickly otherwise it will harden or become brittle.
As it cools you can easily take out the gajak and break in the lines.
Stays good for a week in room temperature. Perfect to enjoy as after meal snack.