To prepare keoti dal, mix the split black urad dal and chana dal in a bowl. Wash well and soak covered in water for 1-2 hours.
Wash the soaked dal, by rubbing it gently. Some of the skins of the split black urad dal will come off and float on top. Skim that off and discard.
Place the soaked and drained dal in a pressure cooker. Add 2 cups of water, grated ginger and salt.
Pressure cook for one whistle and then on sim (lowest flame setting) for 10 minutes.
Once the cooker cools, open the lid. Add the turmeric powder and slit green chillies. Simmer this for 1-2 minutes, mashing the dal gently.
While the dal is cooking in the pressure cooker, you can prepare the tadka on the side.
Heat the ghee in a small pan. Saute the asafoetida into the ghee.
Fry the cumin seeds and whole black peppercorns for a few seconds.
Add the onions, garlic and ginger. Sauté on a low-medium flame for 6-8 minutes until the onions are lightly browned. Transfer this over the dal.
Garnish with fresh coriander is optional.
Enjoy keoti dal with steamed rice. Serve along with fresh salad of cucumber, onion and tomatoes (kachumber).