Make your spice mix first. Dry fry the coriander seeds, cumin seeds, peppercorns, fennel seeds, mustard seed and fenugreek seeds then crush in a mortar and pestle or spice grinder. Set aside.
Place the fish in a large bowl with the salt and pepper, tomato, spring onion, ½ the onion, the red pepper, scotch bonnet, ½ teaspoon of the spice mix and 2 teaspoon of the curry powder. Mix together gently then cover and marinate in the fridge for an hour.
Place the flour on a plate and heat a few inches of vegetable oil in a wide pan over a medium-high heat. Place each piece of fish in the flour to coat and then into the hot oil for 2-3 minutes on each side. Place the fish pieces to drain on a paper towel lined plate.
Heat the 2 tbsps of oil over a medium heat and add the rest of the onion and garlic and cook gently for a few minutes. Add the rest of the curry powder followed by the marinade you used for the fish. Add 200ml of water to the bowl you used for the marinade to collect all the bits left in the bowl then pour the lot into the pan. Cook for 5 minutes.
Add the fish pieces back to the curry sauce and heat through for another 5 minutes. Serve with the rice and peas (recipe below) and a sprinkling of chopped coriander.
For the Rice and Peas
Heat the oil in a frying pan or large saucepan. Add the onion and fry for a few minutes until softened. Add the rice, water and coconut milk and bring to the boil.
Add the gungo peas, cover and cook for 20 minutes until the rice is cooked.