Heat the oil in a deep pan and add the mustard seeds to it. Once they crackle, add the curry leaves and the onion, chillies, turmeric powder, carrots, potato and green bell pepper. Lower the heat and cover and cook till the potatoes are almost cooked.
Add the oatmeal and poha, sprinkle a little water and cover and cook for a couple of minutes. Add salt and mix well.
Once the poha is also cooked, remove from heat, squeeze the lime and garnish with cilantro. Serve hot with a cup of hot chai.