Heat the oil in a pan and add the mustard seeds, cumin seeds and asafoetida.
When it starts to crackle add the tomato puree, green chilli paste, and ginger and garlic paste. Sauté on a medium flame for a minute. Add chilli powder, salt, sugar, turmeric, cumin and coriander powder, lemon juice, garam masala and a tablespoon of coriander leaves