Wash the dal and soak in sufficient water for about 30 minutes.
Pressure cook the dal with two glasses water, chopped onion, tomato, green chillies, garlic, curry leaves, turmeric powder and salt to taste. Pressure cook on a high flame till one whistle and then simmer for 15 to 20 mins or till the dal is done.
Heat oil, add cumin seeds and asafoetida and fry for a few seconds.
When the cumin seeds splutter add the red chilli powder and pour this tempering on the dal.