Heat a nonstick pan with oil, add the fennel seeds and nigella seeds and sauté on a medium flame for a few seconds.
Next, the peeled raw mango cubes, mix well and cook on a medium flame for 2 minutes, stirring continuously.
Add 1/4 cup of water, coriander powder, chilli powder, turmeric powder, sugar and salt, mix well and cook on a medium flame for 2 to 3 minutes with lid covered.
Allow the launji to cool completely.
Once cooled, serve or store in an airtight container and refrigerate.