Heat 1 tbsp of oil, add cumin, garlic, greenchilies and saute for a few minutes. Now add roughly chopped tomatoes, sugar and tamarind; saute until the tomatoes turn pulpy. Keep it aside.

When the mixture is cool, add salt and grind to a smooth or coarse paste. Heat the remaining oil, crackle the mustard, add urad daal, curry leaves and mix it in chutney. Serve with dosa or idly.