Briefly rinse 1½ cups of thick poha until softened but intact. Drain well. Mix gently with 1 teaspoon of sugar, ¼ teaspoon of turmeric and salt.
Dry-roast 2 tablespoons of peanuts until crisp; set aside. Heat 2½ tablespoons of oil and fry 1 peeled diced medium potato until golden and tender. Lift out.
In the remaining oil, let ½ teaspoon of mustard seeds crackle. Add ½ teaspoon of cumin seeds and ⅓ cup of chopped onion; cook until soft.
Reduce the heat. Add 8 curry leaves, 1 teaspoon of chopped green chili and the peanuts. Stir for 1 minute.
Add the potato and poha. Mix gently, cover and steam over low heat for 2 minutes. Turn off the heat and leave covered for 2 minutes.
Mix in 2 tablespoons of freshly grated coconut, 2 tablespoons of chopped cilantro, and 2 teaspoons of lemon juice.