Soak the toor dal for 30 minutes. Wash and pressure cook the dal with 1 ½ cup water for 3 visiles. Set aside.
In sauce pan heat 1 ½ tablespoon of oil and fry the pavakka or bitter gourd pieces for 5 minutes.To this add ½ cup of water , salt and turmeric. Let it cook for another 10 minutes.
In the mean time in a small skillet heat one teaspoon of oil and roast chana dal, coriander seeds, urad dal, pepper corns , Red chili until raw smell is removed and nice aroma is released this takes about 2 minutes and set aside. I prefer to roast them one by one. In the same pan add coconut and fry until they turn slight brown in color. Keep aside. Once everything is cooled grind everything into a coarse fine paste. And set aside.
Heat tamarind with ½ of cup of water in microwave at high for 15 seconds and extract juice and set aside.
Once the bitter gourd pieces are cooked then add tamarind juice and jaggery bring it to a boil. To this add ground paste and mashed cooked toor dal and again boil for 2 minutes or until spices are distributed uniformly.
In mean time heat a small skillet and add oil and mustard, asafetodia, curry leaves and when mustard seeds start spluttering remove from the heat and add it to bitter gourd curry.
Enjoy with hot rice.