To begin making Kothavarangai Paruppu Usili recipe, soak Toor Dal in water for about an hour. 

Meanwhile, add finely chopped cluster beans/kothavarangai/gawar phali to a pressure cooker along with salt to taste, 2 tablespoons water and turmeric powder. Mix well. 

Pressure cook for 2 whistles and release the pressure immediately by running the pressure cooker under water. Open the cooker lid and keep aside.

After 1 hour, drain water from soaked Toor Dal. Add the drained Toor Dal along with red chillies and salt in a mixer.

Coarsely grind the ingredients and keep aside. Make sure to grind the soaked dal coarsely by adding no or very little water. 

Add water in the idli pan for steaming, grease the idli plates with little oil and add the coarsely ground paruppu usili mixture to the idli plates.

Steam the paruppu usili for around 1o minutes until the ground toor dal is cooked completely. Turn off the heat, remove the steamed toor dal, crumble it and keep aside. 

The next step is to temper the Kothavarangai Paruppu Usili.

In a pan, add a tablespoon oil. Once the oil is heated, add the mustard seeds, urad dal and curry leaves. 

Once the mustard seeds sputter and dal turns golden brown, add steamed paruppu or toor dal into the pan and fry it for a few minutes. This will help the dal lose the moisture if there is any, so that it gives the crumbly texture. 

Next, add the cooked Kothavarangai/Gawar Phali and give it a good mix. Adjust salt according to your taste. 

Mix well, keep it covered for 2 minutes and turn off the heat. Transfer the Kothavarangai Paruppu Usili to a serving bowl and serve hot.

Serve Kothavarangai Paruppu Usili along with Mor Kuzhambu, Steamed Rice and Elai Vadam for a delicious Sunday lunch.