Wash and wipe the green chilies and cut them into roundels. I have not deseeded them as the variety I used was not very spicy. If using very spicy chili, I would suggest that you partially deseed them to help reduce the heat.
In a pan, heat the oil. Then add the mustard seeds, fennel seeds and Asafetida.
Fry for 30 seconds and then add the turmeric powder and the green chilies.
Sauté for about 2 minutes and then add the salt. Mix well and then cover the pan and cook the chilies for about 4-5 minutes until they are slightly soft.
Now add the coriander powder, amchur powder and the salt and mix well.
Cook for couple of more minutes and then turn off the flame.
Let it cool down entirely and then transfer it to a glass jar and store in the refrigerator. I had left it out for 2 days and it remained fresh. It was done by then so cannot say how long it can be outside. :)