Dry roast the sesame seeds in a hot pan for about 3 to 4 minutes. Once they are done, pour them into a bowl. (Pro tip: I keep stirring the sesame seeds over a low flame; even slight scorching can leave the laddus bitter.)
Then add half a cup of water to the hot pan.
Add the jaggery and let it melt.
Check the consistency of the melted jaggery. Drop a small quantity of melted jaggery in the water. If it becomes solid and hard, it means the melted jaggery is ready to make laddus. Turn off the gas stove. (Pro tip: I rely on the cold-water test rather than color alone to judge when the jaggery is ready.)
Brush some ghee on a flat plate and keep it aside.
Add dry roasted sesame seeds to the melted jaggery.
Gradually mix the dry roasted sesame seeds with melted jaggery.
Pour the mixture on the flat plate already greased with ghee. (Pro Tip: I let the mixture cool down a bit to shape them with my hands. If it is very cool, forming firm rounds becomes much more difficult.)
Apply a little ghee in both hands to prevent it from sticking. Shape the mixture into round laddus using both hands.