Wash the Narthangai and wipe it with a clean cloth or paper towel. Ensure no water content on the Narthangai.
Keep one Narthangai aside (we need it for taking out the juice at the end).
Cut the remaining 4 Narthangai into small pieces. Keep the Narthangai in a Broad plate and cut it so that the juice while cutting will stay in the plate. Remove the seeds. Put the cut pieces along with the juice into a ceramic jar. Add salt and shake the jar well. Cut the remaining Narthangai into two and squeeze out the juice on top of the cut pieces. Again shake it well. Close with lid and keep aside.
Everyday morning and evening shake the jar well and leave it. Repeat this for 3 to 4 days. If needed, you can use a wooden spoon and mix it well. At the end of 4th day, you may find the pieces soft (it will not be too soft, just right to eat) and skin colour changed. If it is not soft, then you can keep it for one more day.
When it is soft and eatable, add red chilli powder and turmeric powder and stir well.