Peel the plantains(unripe) and cut inti thick slices. Heat 3 tsp of oil in a fry pan, add mustard seeds, when it pops, 1 tsp urud dal. Add the plantain pieces and 1/4 cup of water and allow it to boil. Add 1 tsp salt, 1 tsp red chillie powder, a pinch of tamarind and cook until the plantains are tender. Then roast (add oil if required) for about 5 min.