Soak the poha for about 5 mins in water enough to cover it after rinsing it thoroughly.
In case you are using the thin variety, all you have to do is just wash it thoroughly under running water and set aside for 5 mins. If you are using the thicker ones, then soak the poha for 5 mins in 1 cup of water. After 5 mins, drain the water and set aside.
Now, grind together the coriander, green chilies, curry leaf and lemon juice adding little water to a fine paste.
Use your coffee grinder for this and you will be done quickly. But remember little water are the operative words here. You add too much water and you will have a soggy poha.
Now heat oil in a pan.
Add the mustard and pop them. Once popped, add the urad dal.
Once the dal turns a light brown, add the onions and saute them till light brown.
Now toss in the potatoes and cook till tender.
Next, add in the soaked poha, salt and ground paste and mix well.
Cook closed on low flame for 2 to 3 mins.
Once done, serve hot with curd or sev and onions.