Clean, Wash and Chop the Greens. I usually do this ahead. It can also be done just before cooking, paruppu keerai/purslae, doesn't take much time for cleaning and chopping.
Soak the whole masoor dal in water for 15 minutes. Drain and keep aside until use
Heat a pressure cooker with oil for tempering. When the oil is hot, splutter mustard seeds, add green chilies, hing and curry leaves.
Next add chopped tomatoes to this sizzling tadka. Add turmeric powder and saute for a minute
To this add chopped paruppu keerai/purslane leaves and mix well. Add the drained masoor dal to the keerai.
Add 3 cups of water to the keerai. Add sambar powder, freshly grated coconut and salt to this and mix.
Close the pressure cooker and pressure cook for 3-4 whistles. Once done, let the pressure release on its own.
We prefer our kootu to be semi-gravy, not so thick or thin. If you feel the consistency of the kootu is thin, let it boil for 10 minutes to get to the right consistency.
Once done, remove from the stove, serve it along rice or roti.