In a heavy frying pan heat the oil and saute the onion until golden. Add the chile, tomato and mango and fry a little longer. Pour in the coconut milk and water and bring to a boil. Add the tumeric, paprika, ground coriander, and salt and simmer 5 to 10 minutes.
Rub the curry leaves between your palms to release the flavor, and add them and the fresh coriander to the mixture. Add the lemon juice and simmer for a further 10 minutes.
If you are using the eggs hard-boiled, add them to the sauce and heat through for 5 minutes. If to be poached, break the eggs gently into the mixture and cook for 3 minutes.
This dish can be served with rice or with snippets of toast or good bread to mop up the delicious juice.