Heat oil in a non-stick pan, add cumin seeds and saute till they change colour. Add garlic paste, ginger paste and green chillies and saute till the raw smells disappear.
Add onion and saute till it becomes translucent. Add red chilli powder, turmeric powder, coriander powder, cumin powder and garam masala powder and saute 1 minute.
Add tomato and salt and continue to saute till tomato becomes pulpy.
Add eggplant, mix, cover and cook till the eggplant is done.
Add potatoes and mix well. Cook on medium heat till the potatoes are heated through.
Transfer into a serving bowl, garnish with coriander leaves and serve hot.