Wash and soak the dal for 30 minutes.
Peel and dice the mango.
Pressure cook the dal for 3 whistles. Let the pressure subside naturally.
Add the salt, turmeric powder and raw mango to the dal and pressure cook for 1 whistle.
Let the pressure subside on its own.
Add a cup of water if the dal is too thick for your preference.
In a kadai/saucepan, heat oil, add cumin seeds and when they crackle add the ginger, garlic, chillies and onion and saute the onions to light brown.
Add the cooked dal and bring it to boil. Simmer for 5-7 minutes.
Check the salt and adjust according to your taste.
Serve hot with rice or roti.