You don’t have to pan roast/ toast the lentils. I do because the Parippu Curry develops much better flavor. Start by pan roasting the lentils in ghee, on medium heat till they just start changing colour and give off a nutty aroma. Stir frequently and do not brown the lentils. Substitute ghee with coconut oil for a vegan dish.
I prefer to cook the lentils at this point, with the turmeric powder in the pressure cooker till very soft. You can cook them in a pot on the stove but it will take much longer.
While the lentils are cooking, grind together the coconut, cumin seeds, sambhar onions and green chillies with a little water to a smooth paste. Keep aside.
Take the cooked lentils out of the pressure cooker and mash well. Put this in a pot, adding a little water if necessary to adjust the consistency, and bring to a boil. Turn the heat down to low, and stir in the coconut paste. Add salt to taste. Cook for another 5 minutes till well blended but do not bring to a vigorous boil. Take the pot off the heat.
Heat the coconut oil in a tempering pan or small pan. Add the mustard seeds. When they pop, add the sliced sambhar onions and sauté over medium heat, till they caramelize and turn golden brown. Stir in the red chilli pieces and curry leaves and immediately pour it all into the cooked lentil curry.
Stir and serve with hot rice and other accompaniments.