Cut tomatoes, green chillies and chop coriander leaves.
Heat oil in a kadai, add green chillies, red chillies, coriander and tomatoes also.
Add salt, turmeric powder and asafoetida. Saute well. Cook them till the tomatoes become mushy.
Once the tomatoes turn mushy, spread this to a wide plate to cool it.
Meanwhile, prepare tadka. Heat oil in another kadai, add mustard seeds, black gram, fenugreek