1- Put the fish steaks in a large bowl. Sprinkle with salt and half the turmeric and mix together, making sure the fish is well coated. Set aside to marinade for a few minutes

2- Heat a small frying pan over a high heat and fry the mustard seeds for 1–2 minutes until lightly toasted and fragrant and beginning to pop. Tip into a pestle and mortar and pound until finely ground, then set aside.

3- Heat a large non-stick pan over a medium heat and add the vegetable oil. Once hot, tip in the onions and fry for 8–10 minutes over a medium-low heat until starting to colour. Season with salt and continue to cook for a few more minutes until lightly golden.

4- Add the pounded garlic to the pan and cook for 2 minutes, stirring constantly before adding the remaining half teaspoon turmeric, chilli powder, ground coriander, garam masala and paprika. Mix together and stir over a low heat for a further 2–3 minutes. When the mixture gets dryer, add 250ml/9fl oz boiling water to loosen and cook for a minute before adding 2 heaped teaspoons of the pounded mustard seeds (reserve the rest for another usage). Allow to cook gently for 3-4 minutes while stirring

5- Wash the fish by rinsing well with cold water. Then add to the pan along with enough hot water to cover the fish (approximately 150–200ml/5½–7fl oz). Swirl the pan to cover the fish in the sauce. Cook gently for around 6–8 minutes, carefully turning the fish halfway through cooking. The curry is ready when the fish is opaque and cooked through and the sauce has started to thicken (it should have a loose consistency). Add the freshly chopped coriander and season to taste with salt.

6- Heat for another minute, don’t stir the pan as this might break up the fish – just give the pan a gentle swirl or shake. Serve the fish curry with sliced green chilli, extra coriander leaves and basmati rice.