Heat a pan with oil, once it is hot add cumin seeds, coriander seeds, curry leaves and garlic pods. sauté well for few minutes.
Next, add chopped onions and green chillies. Fry for few minutes or until onions turns their colour slightly.
Then add chopped tomatoes, turmeric powder and salt. Sauté for 5 to 6 minutes on medium flame.
Now cover and cook the tomatoes on medium flame or until tomatoes becomes soft and mushy.
Once tomatoes are cooked nicely, add coriander leaves and red chilli powder. Mix well and sauté for another 2 to 3 minutes. Switch off the heat and allow the mixture to cool.
Then transfer the mixture into a mixie jar and grind into a coarse paste and transfer to a bowl.
Next heat a small pan with 2tsp of oil. Add mustard seeds and urad dal and allow them to crackle.
Mix the tempering into the tomato chutney well.