Wash the toor dal and chana dal and soak it along with dried red chilies for 30 to 45 minutes. You can soak up to 1.5 hours.
Preparing the Usili | Grinding, Steaming and Crumbling the lentils
Grinding the lentils
After 30 to 45 minutes, drain all the water from the lentils.
In a blender or mixer jar, add the drained lentils along with red chilies. Add 1.5 tsp salt (or to taste), ¼ tsp ground turmeric, and ⅛ tsp hing. Sprinkle water as required and grind it into a semi-smooth paste.
Note - The lentil texture is a personal preference. You can grind it smooth or slightly coarse as well. Also, do not add all water at once. Add as required. It should be a thick paste.
Steaming the ground lentils-
Grease the idli plates with oil and add 1 cup of water to the idli cooker or pressure cooker.
Take a handful of the ground lentil mixture and place it in the idli plate. I got four big balls like below. You can also steam it in a greased plate.
Now place the idli plates inside the cooker. I used my pressure cooker to steam the lentils. In the case of a pressure cooker, do not add the weight. Steam it for 10-12 minutes.
Crumbling the lentils-
Once the pressure is off, remove the cooked lentil cakes.
Crumble them nicely like below and set aside. That's it. The usili is ready.
Steaming the veggie-
You can cook the vegetables in parallel. You can steam them in your preferred way either steam in Instant Pot or open-pot method or stove-top pressure cooker. I love to cook my dal for sambar, rice and second veggie for kootu in stackable pans in the stove-top pressure cooker. So I went with that. We cooked plantain-flower with toor dal, chayote squash for kootu, and rice all at one time like below.
Pressure cook the veggie by adding salt, ground turmeric, and ¼ cup of water for three whistles in a stove-top pressure cooker.
Once the pressure is off, set aside the vegetable.
Note - As we were cooking rice, dal, and chayote squash in stackable pans, we went with three whistles. We kept the banana flower pan at the top. But if you are cooking banana flower alone, cook it for one whistle or at the max two whistles but not more than that.
I haven't tried steaming banana flower in the Instant Pot. So I am not able to give precise timings. I will update this post as soon as I try it.
Tempering and preparing the paruppu usili-
In a pan, add the oil. When the oil is hot, add the mustard seeds and urad dal. Let mustard seeds splutter and add the curry leaves and saute for 30 seconds.
Next, add the cooked banana flower and saute it for two minutes.
Now add the crumbled lentils and mix thoroughly. Reduce the heat to medium-low. Roast for 5 to 6 minutes or until all the water is absorbed and until light crust forms.
That's it. Yummy vazhaipoo paruppu usili is ready.
Serve hot with vathal kuzhambu or mor kuzhambu.
Adjust the red chilies and salt as per your spice preference.
You can make the usili either with toor dal or chana dal, but of course, the taste will slightly differ.
Depending upon the veggies you use, the cooking time might differ. The veggies should not turn into a mush. That's the key.