Cut onion into cubes and cut green chillies vertically.
Pressure cook toor dal with the onions and green chillies adding sufficient water.
:- Dal should be cooked well.
Grind together coconut with cumin seeds, chilly powder, garlic, turmeric powder and pepper powder in a blender adding enough water.
In a vessel, mix cooked toor dal, coconut mixture and potatoes.
Cook well adding salt and curry leaves.
Cook till the potatoes are done.
:- Serve hot with chappathies.