First we have to soak the poha. Sprinkle the water little by little on the poha and soak the poha. You may need one cup or less based on the type of poha you are using. Set it aside for 10-15 mins.
In the meantime, heat the oil in the pan. Add mustard seeds and asafetida to the oil. Then add the chopped green chillies. As soon as the mustard seeds crackle add onions and sautee for a few mins.
Then add the cut potatoes and a little bit of salt, turmeric and red chili powder. Cover it and let the potatoes cook for a few minutes.
Mix the poha with your hands to make sure they are not stuck together. Add poha to the pan and mix it together. Cover for another few mins. Add lemon juice and garnish with cilantro, tomatoes, red onions. Serve hot.