Wash the beans, and string them. Trim off both ends of each bean and then finely chop the beans. If there any beans which are a bit mature, shell them and discard the pods.
In a pan, heat the oil (coconut oil gives an authentic flavour and taste) and add the mustard seeds. When they splutter, add the black gram lentils and sauté till they brown.
Now add the curry leaves, stir once and add the beans. Stir fry the beans for a couple of minutes, then add half a cup of water. Add the salt and turmeric powder and bring to a boil.
Turn down the heat and allow the beans to cook till done and the water has evaporated completely.
