Soak the lentils overnight or for at least for 4-6 hours. After soaking, rinse the lentils in running water until the water runs clear.
Peel and finely chop the ginger.
Drain all of the water from the lentils and transfer into a heavy bottom pot. Add 800 ml water and bring to a boil. Remove the scum/foamy bits from the top. Reduce the heat to simmer.
Add the turmeric, ginger and salt. Cover and cook for 20 minutes or until the lentils are soft and mushy.
Tadka/Tempering
Heat the oil in a small pot or pan. Add the cumin seeds, followed by asafoetida and chilli powder. The process of tempering takes less than a minute, so be quick and be careful not to burn the spices.
Add the tadka to the daal, give it a stir and serve.