Simple chutney that goes great with dosas and idlis.
Heat a pan and roast the peanuts, tamarind, garlic, pearl onions until the peanuts are slightly golden. (If you are using peanuts with skin, remove the skin after roasting)
Add it a blender along with salt, 1 cup water and grind it to a smooth paste. Add more water half way through to bring it to the consistency you require.
When done, make a tadka by heating oil in a small pan and add the mustard seeds, asafoetida, and curry leaves. When the curry leaves splutter add the tadka to the chutney. Serve chutney with idlis / dosas.