Peel and cube the chow chow into 1 inch pieces.
Soak the tamarind and extract the pulp. I normally store tamarind extract for easy usage.
Wash and take the toor dal in a pressure cooker, along with the vegetables, chopped tomatoes, and turmeric powder. Pressure cook for 2 - 3 whistles or till the dal is cooked well.
Once the pressure falls, remove the lid, add the salt, sambar powder, tamarind extract, and coconut paste along with enough water. Bring to a boil.
Meanwhile, in another pan, heat the cooking oil. Add curry leaves, mustard seeds urad dal, dry red chilies, sauté well.
Then, add chopped onions, add the hing, and when the onions turn colour, and pour this to the boiling dal.
Simmer for a couple of minutes, add coriander leaves and remove.