Firstly, in a wok add oil and heat it.
Into it add cumin seeds and let it splutter.
Add garlic cloves and saute for few minutes.
Into it add green chillies and saute for few minutes.
Add tamarind pieces, chopped coriander leaves, stir and cook for few minutes.
Cool down the whole mixture.
Add the mixture into a blender, add salt into it and blend the mixture into a coarse or fine paste.
Serve it with idli or dosa etc...