Bring water to a boil, add in salt and turmeric powder and mix well. Add in the drained dal and cook for 5 mins or so,, till it is tender. You have to keep a close eye to this.
Now drain this and set aside.
Heat oil in a pan, add in mustard, urad dal, chilli, curry leaves and asafoetida and sizzle for a min.
Now add in dal and mix well. Season with salt if needed.