1.Wash ,string and cut beans in to fine round pieces .
2. Chop onion and green chilies .
3. Heat oil ,add mustard seeds .
4. When mustard seeds crackle ,add chopped onion ,green chillies ,and curry leaves .Saute .
5. Add sliced beans ,salt and enough water to cook beans.
6. Cook till beans are done and all water has evaporated .
7. Add grated coconut ,cook a little longer ,stir well and remove from fire . Serve hot .