Wash dal couple of times in running water.
Add the dal to pressure cooker along with onion, chopped tomato, ginger, green chilli, turmeric powder,salt and 2 cups of water. Cook for 4 whistles in medium flame and put off the stove.
Once the pressure releases completely, open the cooker lid. The dal should be cooked soft and mushy. Add little water if the dal is too thick.
Transfer the cooked dal to serving bowl and garnish with chopped coriander leaves..
In a small pan, heat 1 tbsp of ghee keeping the heat medium.
To this add mustard seeds. As they crackle add cumin seeds, chopped garlic, dried red chilli, asafoetida and curry leaves. Fry this for 1-2 mins.
Pour the tempering to the dal and mix it.
Serve the dal with steamed rice and rotis.