Wash daal 3 to 4 times by rubbing between the palms and changing water every time.
Soak dal for 2 hours. No issues if you soak it for long.
After 2 hours, transfer dal in heavy bottomed pan and add water in it.
Put a lid and Initially keep the heat at high temperature.
When water begins to boil, lower the heat.
After couple of minutes, you will find white foam over the surface of the dal. Remove and discard that.
Then add butter, hing, salt and turmeric powder. Mix.
Now put the lid and leave the dal to boil on low heat. As long as enough water is there, you are not bound to stir the dal.
In almost half an hour to 45 minutes, dal will turn soft but we need the batter like texture and consistency.
Keep cooking, keep mashing and keep stirring.
Also scrap the sides of the pan as dal will begin to stick there as well.
Soon you will find there will be no grain at all and it's all smooth and creamy batter like stuff in the pan. Our dal is ready. Off the heat.