Heat a pan add black and white sesame seeds and dry roast over medium flame for a couple of mins. Transfer to a plate and let them cool. In the same pan dry roast flax seeds on low flame till crackling sound and nice aroma comes out remove from the pan, keep aside and let it cool. Once cooled grind them into powder and place into a mixing bowl.
Now mix the ground powder, jaggery and pulse again for 30 secs, then transfer to a mixing bowl and mix thoroughly with hand. Take some amount of the sesame mixture and make into small lemon sized balls. Now healthy and tasty recipe black sesame flax seeds laddus are ready, store them in an airtight container.