Fresh ginger, Green Chillies, together to a fine paste.
In a kadai put the oil and when it is hot add cinnamon stick, cardamom, cloves and fennel seeds. When it is slightly fried, add chopped onion and fry till it turns transparent. Add tomato pieces along with salt, turmeric powder, red chilli powder, coriander powder and stir it. Fry till tomato mashed well. Now add potato pieces and mix well. Add the ground paste. Mix once again everything well and add enough water to cover the potato. Close with a lid and cook till it starts boiling. Allow to boil for few more seconds. Remove from stove, add kara boondhi and stir well.