Shell the boiled eggs, cut them in half lengthways and set aside.
Heat oil in a medium, lidded saucepan over low heat, then add the mustard seeds. Let them cook for a few seconds until they pop, then add the onion and curry leaves and stir-fry for a few seconds. Add the garlic, chillies, fenugreek and cumin seeds, and sauté until the onions are soft and turning golden.
Add the turmeric and give it a stir. Add the coconut milk, water, curry powder and salt, and mix well. Bring to the boil, then reduce the heat, half-cover the pan with the lid and simmer for 8-10 minutes until the sauce has thickened.
Gently slide in the halved eggs, then half cover with the lid again and simmer for a further 5 minutes. Taste for salt, then remove from heat and serve.