In a mortal-pestal, add green chilli, ginger, garlic, curry leaves and some coriander leaves. Crush it into coarse paste. Keep it aside.
In a mixing bowl, mash boiled potatoes and keep it aside.
Now in a pan, add oil, mustard seeds, cumin seeds and hing. Sauté for a minute.
Then add coarse paste. Sauté for a minute.
Now, lower the flame and add turmeric powder, coriander powder, garam masala and salt. mix well.
Switch off the gas and add tempering into boiled potatoes.
Also some coriander leaves and lemon juice. mix well.
Aloo masala is ready.
Make a round shape ball from masala and keep it aside.