Wash the coriander leaves under running water and spread on a paper for drying. Let it dry completely and become moisture less. Chop it finely and keep aside till use.
Method
Take the chopped coriander leaves in a mixer. Include tamarind and green chillies too. Grind it in to fine puree without adding any water.
Next dry roast the fenugreek seeds and mustard seeds till they splutter or change color. Then powder them together using mortar pestle.
Heat a pan adding oil and mustard seeds. When they spluter pour the coriander leaves paste. Add salt and jaggery.
Stir in for some time till the jaggery and salt mix. The color changes to pale green now.
Finally add the mustard plus fenugreek powder and give a nice mix. Continue cooking for few more seconds and switch off the flame.
Spicy and aromatic coriander leaves thokku is ready to serve with curd rice.
Notes
Ensure the coriander leaves are dry and moisture free before grinding. It will increase shelf life.
You can use red chillies too substituting green chillies.
Increase or decrease the chillies to adjust spice.