Rinse the vanpayar under running water a few times. Pressure cook vanpayar with 3 cups water for 8 - 10 whistles on full flame. Switch off the gas and let the pressure drops. Open the cooker and strain the cooked vanpayar. Keep aside 1/4 cup of cooking water.
Crush together sliced small onions, chopped garlic, black pepper, fennel seeds and dry red chilli.
Add turmeric and chilli powder to grated coconut. Mix well using your fingertips (njeraduka).
Heat oil in a wide pan. Add crushed ingredients, curry leaves and cook till it browns, and raw smell goes, around 4 - 5 mins.
Add coconut mixture and mix well. Cook for 3-4 mins.
Add cooked vanpayar and salt. Mix well. Add reserved cooking water (refer notes) and cover and cook for 6 - 8 mins. Remove from fire.