In a pan, heat mustard oil. Add cumin, fenugreek seeds and mustard seeds. Let them splutter.
Add potatoes with some salt, let it cook on low flame
Once the potatoes are semi cooked, add the eggplants with ginger,chilly & garlic to it and mix well.
Cook for 8-10 minutes, add all the spices to the pan and mix well. Let it cook until the rawness disappears.
Add the chopped tomatoes to the pan, let it cook on slow flame
Add ¼ cup water and let it cook until the tomatoes have soften and potatoes are cooked.
Mix well. garnish with fresh coriander, Serve hot with roti or rice.