Prepare the green gram for cooking as mentioned above. Once you have soaked gram ready, proceed with the steps below
Place the payaru in a pressure cooker vessel and add enough water to cover it by an inch or so
Pressure cook for 4-5 whistles (about 15 minutes)
Wait for the pressure to be released and check to see that the beans are cooked. They should hold their shape but turn mushy when squished between your fingers. Don't worry if the beans are undercooked, just return to the cooker and pressure cook for another ten minutes or so. And if they are overcooked, well, that's fine too. They won't look as good but will taste good either way
Heat oil in a kadai or pan and add the mustard seeds
When they pop, add the chillies and curry leaves. Take care during this step, the oil will splutter due to the moisture in the curry leaves
Fry for 10 seconds and then add the hing powder
Give it a quick stir and add the cooked beans
Stir well and let the tempering mix well with the beans
Add salt, mix again
Now add the grated coconut (you can use freshly grated coconut or frozen coconut that's been thawed)
Mix again, taste to make sure there's enough salt, and remove from heat
Serve warm but room temperature sundal tastes just fine too