Chop the potatoes and tomatoes and keep aside. Heat oil in a pan/kadhai. Add in mustard and cumin seeds. Wait for them to sputter.
Now add in the asafoetida. Fry for a minute. Add in the tomatoes and some salt. Let the tomatoes soften, release their water and cook. Add a little water if needed.
Now add the turmeric, garam masala, cayenne and salt and tip in the potatoes. Mix well. Cook for a couple of minutes.
Add some water for a slight gravy. Cover and cook for a few minutes more. Now taste and adjust the seasoning. Your tari wale aloo tamatar is ready.
Serve hot, garnished with coriander leaves.
1. You can mash the potatoes a bit to make a slightly thick curry.
2. You can also make it dry by avoiding the use of any water.
3. This is perfect with rotis, pooris and parathas and is the easiest curry to get right.