grind together ginger, garlic and green chilli to a fine paste and keep aside until use.
heat few drops of oil in a pan and roast coconut pieces, sesame seeds and cashews until slightly brown and grind to fine paste. keep aside until use.
heat oil in a a pressure cooker and add fennel seeds, cinnamon, cloves, curry leaves. and green paste. fry for few seconds.
add chopped onions and fry for a minute.
to this add all the remaining ingredients. tomatoes, tapioca, salt, turmeric powder, chilli powder, prepared coconut paste.
mix well and add 1.5 cups water. close and pressure cook for 4-5 whistles on high flame.
let the pressure settle. open and mix well. serve hot with roti