Wash the toor dal well, 3-4 changes of water, soak the dal for 30 minutes.
Pressure cook the dal with two cups for water, salt and 1/2 teaspoon turmeric powder.
Once the pressure cooker cools down naturally, open it and strain the liquid from the thick dal.
Transfer the thick dal/Lachko to a serving bowl.
Palce a deep saucepan on medium flame.
Add the oil/ghee, heat it. Add mustard seeds, cumin seeds, cinnamon stick, asafetida.
Add the Dal water to it.
As it boils, add the jaggery, curry leaves, kokum, ginger+chili paste.
Adjust the salt, add if needed.
For the lachko.
In a tempering karhai, add the ghee and cumin seeds. Once the seeds sizzle pour the tempering over the lachko dal.
Serve steaming hot Osaman with Lachko and Rice.