Heat oil in a pan and when the oil is hot enough, add cumin seeds. When they sizzle, add curry leaves, chopped onions and just sauté. Add thin sliced potatoes pieces and cook on medium heat. Add a pinch of salt and mix well. Cover with lid and cook for few minutes till the potatoes are transparent or half cooked. Add turmeric and chilli powder. Take masala lijjat papad and break them into pieces and add in the pan. Mix well, cover and cook on a slow flame. Cook till the papads are dry and slightly crispy. Add some chopped tomatoes, 2 tsp ground coconut (optional). Mix and cook for another 3-4 minutes. The dish is ready to be served.