Traditionally as Valli mentioned, these seeds were washed
and then sun dried which is what I did. Made use of the too hot weather outside for this purpose. It dried out within 10 minutes flat!!!
Dry roast them in a tawa and let them cool.
take about 2 - 3tbsp of grated or powdered jaggary
and run in a mixie. The amount of jaggary normally depends on the formation of laddoo. When you make a laddoo, it should stay in shape. Then you know the amount is enough. Also it depends on the fineness of the sesame powder. When you run in mixie, it becomes little oily which will help in holding the laddo shape.
I powdered the black sesame coarsely first
then added the powdered jaggery to the sesame mixture
and pulsed them for few more seconds until they were well combined.
The mixture was oily enough to help me shape them into small balls (or laddos as Indians call them)