Heat oil in a kadhai and add fenugreek seeds and corriander seeds to it.
Then add chopped green chillies and ginger & stir fry it.
Crush the potatoes and add it.
Mix the crushed fennel, turmeric powder, asafoetida, chilli powder and salt in little water to make a smooth paste.
Add the paste to the potato and mix it well & stir fry it.
Add water to it and cover the lid & let it cook on medium flame for 10 minutes.
Remove lid and add garam masala & dry mango powder. Cover lid and again cook for another 10 minutes.
Remove from gas, add ghee and serve hot with poori or kachori.