Ingredients

Step by step

1. Preheat the oven to 200°C, fan 180°C, gas 6. Cook the potatoes in boiling salted water for 15 minutes or until very tender. Drain well and set aside.
2. Meanwhile, cook the onion in the coconut oil in a large frying pan for 5 minutes until starting to soften. Chop the cod into roughly 4cm chunks and toss with 1⁄2 teaspoon of turmeric, a squeeze of lemon juice and a good pinch of salt in a bowl; set aside.
3. Stir the ginger and garlic into the onions and cook for a further 2-3 minutes. Stir in the cumin, 1 teaspoon of mustard seeds and 1⁄2 teaspoon of turmeric, then cook for a further minute.
4. Add half of the coriander to the pan along with the chilli and cook for just 1 minute. Mix a little of the coconut milk with the cornflour in a small bowl, then add to the pan with the rest of the coconut milk and the cherry tomatoes. Simmer for 3 minutes; the sauce should thicken slightly.
5. For the topping, heat the butter in the saucepan you cooked the potatoes in. Add the remaining turmeric and mustard seeds, plus the smoked paprika and cook for 1 minute. Mix in the potatoes making sure they are coated in the buttery spices. Sprinkle with a little salt and the remaining lemon juice. Using a fork, gently crush the potatoes but don’t mash completely. You want lots of texture to create crunchy bits.
6. Remove the curry sauce from the heat. Season to taste, then mix in the fish and rest of the coriander. Tip it all into an ovenproof dish and spoon the crushed potatoes on top, spreading them out well. Bake in the oven for 15-20 minutes until the topping is golden and crusty.
   Tip

   Use any white fish that you like, or replace some of the fish with the same weight of peeled raw jumbo prawns.