Fry dal, until golden brown.
Grind it in a blender.
Cook dal in a vessel along with 2 cups of water and turmeric powder.
When it is half cooked, add potato.
Add tomato, green chillies, onions and salt.
Cook, till they are done.
Heat a little oil in a pan.
Splutter mustard seeds.
Fry some onions, red chillies and curry leaves.
Pour this seasoning into the above curry,
:- Serve hot with rice, chappathis, rotis etc.