Heat the vegetable oil in a large non-stick sauté pan over a medium-high heat. When hot, add the onion and cook for 5 minutes or until softened and starting to brown.
Add the garlic, ginger and chilli and cook for a couple of minutes. Now add the curry leaves, turmeric and ground coriander and cook, stirring for 1 minute or until fragrant.
Add the tomatoes, stock and lentils to the pan. Stir, bring to the boil over a medium heat and simmer for 12–15 minutes or until the sauce is thickened and the lentils are tender.
Meanwhile, cut the monkfish into 4cm pieces. Trim the green beans and cut them in half.
You don't need to cook monkfish for long. Add the monkfish pieces and coconut milk to the pan and cook over a gentle heat for 2–3 minutes. Add the beans and cook for a further 3–4 minutes. Remove the pan from the heat, taste to check the seasoning and stir in the coriander. Serve with naan or rice pilaf, and enjoy with a glass of chilled white wine.