Combine tamarind and 1/4 cup warm water in a small bowl and set aside.
Rinse dal a few times.
Add dal, 3 cups of water and quartered tomato to the instant pot.
Set instant pot to pressure cook for 12 on high, allow natural pressure release for at least 5 minutes.
Carefully let the pressure release.
Add grated ginger, salt, and jaggery.
Using an immersion blender, blend until smooth.
Remove the pureed dal from the Instant Pot insert and set aside.
After returning the insert to the instant pot, set the instant pot to the saute on High.
Add oil to the instant pot, once the oil has warmed, add cumin seeds and mustard seeds. Once the seeds start to crackle, add the curry leaves and asafoetida.
Add chopped veggies (onions and potatoes) to the seasoned oil.
Add sambar masala and 1 cup of water. Stir to combine.
Set Instant Pot to pressure cook for 8 minutes, let natural pressure for at least 5 minutes
Manual pressure release before opening Instant Pot.
Stir tamarind and water mixture, strain (to remove any pulp) add to the veggies.
Add in the reserved dal.
Stir the dal, veggies and tamarind until combined. Taste for additional salt or sambar masala. Once it is to your liking, set Instant Pot to keep warm and until ready to serve.