Clean the chinese potato, wash well and pressure cook with salt, turmeric powder and chilli powder. add just enough water and pressure cook to 2-3 whistles.
Open and keep aside.
heat oil in a pan and add garlic, curry leaves and small onions to it.
fry till brown, take it to a blender. let it cool. in the same pan, fennel seeds, peppercorns, grated coconut and fry till reddish.
furthermore add coriander powder and chilli powder. fry for a minute.
take it to the same blender along with roasted onions and grind them to a fine paste.
add the paste again to the pan, cooked koorka/chinese potato along with the water. add more water if needed.
adjust salt to taste, close and cook the pan for 10 minutes.
open and add thin coconut milk. mix well
while it boils, prepare the tempering. heat coconut oil and crackle mustard seeds, sliced garlic, sliced small onions, curry leaves and salt for frying.
fry until reddish and add it to the curry again. mix well.