Rinse and soak the chickpeas overnight or atleast for 6 hours. Then drain the water and add 1.5 cups of freshwater, and pressure cook for three whistles. If using Instant Pot, pressure cook the beans for 18 to 20 minutes. Drain the water and set it aside.
Prepare the spice powder.
In a small pan or kadai, heat gingelly oil, and when it is hot, add the mustard seeds, toor dal, urad dal, black pepper, fenugreek seeds, asafoetida, and dried red chilies. Roast until the toor dal turns light brown. Now add the curry leaves and turn off the heat. The curry leaves will crisp up in the residual heat.
Let it cool and grind it into a smooth paste by adding ½ cup of water.
Prepare the kuzhambu
Add the rasam podi, tamarind paste, turmeric powder, and salt in a saucepan or kadai in which you are going to make the kuzhambu. I used my soapstone vessel for making this, so I added the spices in that.
Now add 1 cup of water and mix them. And bring this mixture to a boil.
Once the rasam podi and tamarind paste's raw smell is gone, add the chickpeas and cook for two minutes.
Now add the ground paste to the kuzhambu and rinse the mixer jar with ½ cup of water and add that. If needed, add half more cups of water. Simmer the gravy for about 7 to 10 minutes.
Mix 1 tbsp of rice flour with ½ cup of water and make a slurry without any lumps. Add this slurry and the jaggery and add it to the kuzhambu. Let the kuzhambu simmer over low heat for about 7 to 10 minutes or until it thickens. Then turn off the heat.
Prepare the tempering.
In a separate tempering pan, heat the gingelly oil and add the mustard seeds and fenugreek seeds. When the mustard seeds splutter, turn off the heat and add the curry leaves. When the sizzle subsides a bit, add it to the kuzhambu. Serve hot with rice.
You can also use canned garbanzo beans. You can use 1 to 1.5 cups of rinsed canned beans for this kuzhambu.
As always, adjust the salt and spices as per your preference.
Instead of rasam podi, you can also use sambar podi.
I highly recommend gingelly oil or peanut oil for this kuzhambu, as it adds a nice flavor.
It's typically a kuzhambu recipe without any onion and garlic. But you can add five cloves of garlic and five shallots and saute them first before adding the tamarind water.
Instead of chickpeas, use black chickpeas or field beans, or even kidney beans to make this gravy.