For the rice: In a 6×3-inch round baking pan, combine the rice, oil, salt, and water. Stir well to combine; set aside. You do not need to cover.
For the chickpeas: In a food processor, combine the onion, tomato, garlic, and ginger. Process until finely chopped. You could also do this by hand.
In the Instant Pot, combine the onion mixture, jalapeño, garam masala, chana masala spice blend, salt, turmeric, cayenne, chickpeas, and water. Stir to combine. Place a tall trivet in the pot over the chickpeas. Place the pot with the rice on the trivet.
Secure the lid on the pot. Close the pressure release valve or point to Sealing (depending on the model). Select MANUAL/PRESSURE COOK and set the pot at HIGH pressure for 30 minutes. At the end of the cooking time, allow the pot to sit undisturbed for 10 minutes, then quick release any remaining pressure by pointing the pressure release handle to Venting (known as a quick release).
Carefully remove the rice. Use the back of a spoon to mash half the chickpeas until thickened. Stir in the tamarind extract (or the substitute).
Serve the chickpeas with the rice. Garnish with cilantro, if using.
