Set the Instant Pot to saute mode and add oil.
Once it heats, add cumin seeds and let them splutter.
Add ginger and green chili. Saute for a few seconds.
Next, add hing, ground turmeric, chili powder, and ground coriander.
Add 2 tablespoons of water and saute for about a minute.
Add the soaked peas and salt.
Add 2½ cups of water. Mix well and deglaze the pot.
Cancel saute mode and secure the IP lid.
Set the Instant Pot in Bean/Chili mode for 15 minutes.
Do a natural release of pressure for 10 minutes, then do a quick release.
The peas should be well cooked and slightly mushy.
Open the lid and mix well.
Lightly mash some of the peas using a potato masher (this will help thicken the curry).
If the curry is too thick, add ½ cup of water and put the IP in saute mode for 2-3 minutes. Check and adjust the salt at this stage.
Put the Instant Pot back in saute mode.
Add garam masala and tamarind paste. Mix and simmer for 2-3 minutes.
Ragda curry is ready.