Pressure cook the chickpea lentils till done. It should hold its shape and shouldn't be mushy. Drain and set aside.
In a large pan, heat oil. Splutter cumin and mustard seeds. Fry the curry leaves.
Add the cabbage, chillies and salt and mix well.
Sprinkle in the powders and cook, on low flame, stirring occasionally till the cabbage is done. Cabbage will release water when on closed lid.
When the cabbage is almost done, add the drained lentils and mix well. Cook till completely done.
Adjust salt and serve warm with chapathis.