Heat oil in a non stick pan. Cut red chillies into small pieces and add along with asafoetida, cumin seeds, mustard seeds and curry leaves. Sauté for ½ minute and add ¾ cup water.
Roughly chop tomatoes and add along with turmeric powder, coriander powder, cumin powder, red chilli powder and green chillies. Mix well and cook for 2 minutes.
Add salt, sugar and ¾ cup water and mix well. Cook for 5-6 minutes.
Add sev and mix. Cook for 1 minute.