Wash and soak the dal in 1 cup of water.
Heat 1 tsp ghee/olive oil in a pressure cooker and add asafetida and cumin seeds to it. Once the seeds crackle, add onions, ginger, garlic and green chili to it. Saute till onions and garlic are slightly golden.
Drain the water off the dal and add dal to the cooker along with turmeric and salt. Stir for 30 seconds and add 2&1/2 cups of water. If you are cooking in an open pan then use 3&1/2 cup of water.
Pressure cook for 1 whistle and switch it off. If you are cooking in open pan, then it will take good 18-20 minutes for it to be cooked.
Once the pressure escapes, open the cooker. Give it a good stir. If required, add more hot water for desired consistency. Adjust the salt to your taste. Dal is ready to be tempered with tadka.