Wash the poha in a colander. Poha should be moist but not mashed. Add salt and sugar and mix lightly.
Heat oil in a pan. Add mustard seeds and when they splutter add asafoetida and curry leaves. Sauté for half a minute and add onions and continue to sauté.
Add green chillies and mix. Add turmeric powder and mix. Sauté for two minutes and add potato and poha.
Mix and cook till poha is heated through. Add lemon juice and mix lightly. Garnish with coriander leaves and serve hot.