1. Wash the dal in several changes of water. Put dal in pressure cooker with five cups of water and bring to boil. Skim off as much of the foam as possible.
2. Add a half tsp of the salt, turmeric and garlic cloves, then set to pressure cook for 6 minutes.
3. Allow the pressure to release naturally.
4. Add the remaining salt and chili. Put the Instant Pot on the warm setting, and set the temperature to custom at 150 degrees. Stir occasionally to keep the dal from sticking to the bottom of the pot.
5. To make the tarka: heat ghee (or oil) in a small pan over medium heat until hot. Add 2 whole chilis. Allow the chilis to sizzle and darken. They should start to turn black but not burn.
6. Add the mustard seeds. They should immediately begin to sputter. After about 15 seconds, add the asafoetida. After another 10–15 seconds add the tarka to the dal and stir well.
7. Continue to simmer and stir the dal for an additional five to ten minutes.
8. Garnish with a few coriander leaves if desired and serve.