Wash and peel firm green raw bannas using a potato peeler.
Now slice them into thin roundels and blanch in hot boiling water for 2 minutes.
Drain and keep aside (the blanching process is optional ,you can skip this step)
Add salt ,chili powder and turmeric in the banana pieces and mix well.
Heat oil in a wide and heavy bottom pan.
Add urad daal, Mustard seeds ,when seeds start to crackle then add asafoetida, curry leaves and grated ginger
Now add the sliced banana (1/2 quantity)and mix well, try to spread them in a single layer.
Now cook on low heat and keep turn sides in between to avoid burning or sticking to the pan.(you can cover the pan with a lid for 2-3 minutes)
When they get a nice golden colour from both the sides and become soft then remove from the pan and add mango powder or some lemon juice.
Repeat the process from the remaining raw bananas.
Serve hot with sambhar rice or rotis or have as a snack with tea or coffee.