Scrape the coconut. Add 2 tea cups of water and blend. Strain and take out all the milk. Mix coconut milk with plain flour very well and keep aside.

Boil all vegetables, including cashewnuts with green chilles and curry leaves. When the vegetables are soft, add coconut milk-flour mixture along with salt and sugar. Stir properly so that no lumps are formed. Let it cook for 10 minutes.

In a kadai heat oil. Add mustard and cumin seeds. After it crackles add it to the curry. Serve hot.