Heat two tablespoons of the oil in a pan, when hot add the asafoetida and red chilli powder, allow the mixture to sizzle and add the ginger, cook for two minutes.
Add the tomatoes and tomato puree, cook until the tomatoes begin to break down.
Now add the jaggery and water and allow to cook on low for around ten minutes or until the mixtures thickens.
Make a second tempering by adding the remaining oil to a small frying pan, when very hot, add the mustard seeds, curry leaves and dried chillies.
Remove from heat and add to the tomato mixture. Stir well and add salt to taste.