Clean and take the chemmeen in a plate. Heat about 1 Tsp oil in a frying pan, and roast dry Chemmeen. Roast properly in medium flame. Keep it aside for some time.
Take all the required ingredients in a plate.
Grind coconut along with green chilli, 1/2 tsp mustard seeds, salt and some water. Keep this paste separately.
After about 10 minutes, grind the roasted Chemmeen (without water) in crushed form. Keep it aside.
Take curd in a bowl/vessel.
Add ground coconut paste and crushed Chemmeen to the curd. Mix well.
For Seasoning:
Heat some oil in a frying pan, splutter 1 tsp mustard seeds and then add red chilly pieces and curry leaves. Fry in low flame carefully so the chilly pieces do not get burnt. Add the fried ingredients into the curd mixture. Unakka Chemmeen Pachadi is ready. Serve with cooked rice, dosa/idly.