1.Wash and peel cucumber ;cut into 2.5 cm pieces . 2, Slit green chillies .3.Mix together green chillies ,half the turmeric ,cucumber pieces ,salt and enough water to cover vegetables .4. simmer till tender .5 . Grind together coconut , remaining turmeric ,onion and cumin to a very fine paste .6.mix together ground ingredients with beaten curds and a little water if thick .7. When cucumber is cooked ,add curds mixture .8. Heat to simmering point over gentle heat . stirring gently.Do not allow to boil .9.Remove from fire when quite hot .10 . In a fry pan heat oil. Add sliced onion, whole red chilli and curry leaves .When onion browns ,add mustard seeds .When seeds crackle pour over curry.Stir well .