Roast 250 grams of sesame seeds (til) in a pan on medium heat until they turn golden brown. Keep stirring to avoid burning. Once done, transfer them to a plate.
In the same pan, add 150 grams of jaggery (gur) and 1/4 cup of water. Stir on low heat until the jaggery melts completely.
Increase the heat to medium and continue cooking the jaggery syrup until it reaches a hard ball consistency. To test, drop a small amount of syrup into a bowl of cold water; it should form a hard ball that's not chewy.
Once the jaggery syrup is ready, turn off the heat and quickly add the roasted sesame seeds to the pan. Mix well to ensure all the sesame seeds are coated with the syrup.
Pour the mixture onto a greased tray or a rolling board. Using a greased rolling pin, roll the mixture flat to about 1/4 inch thickness.
While still warm, cut the chikki into desired shapes using a greased knife.
Allow the chikki to cool completely before removing it from the tray.
Store the sesame chikki in an airtight container to keep it fresh.