Around the world in 80 dishes No. 34: Bengali mustard fish

Ingredients to serve 3-4

450g halibut steaks, left whole or quartered

Three-quarter teaspoon of turmeric

Salt, to taste

One-and-a-half small tomatoes (about 150g)

3 fat garlic cloves

4–5 green chillies (preferably Indian finger)

One-and-a-half tablespoons powdered brown mustard seeds

4 tablespoons mustard or vegetable oil

One-and-a-quarter teaspoons nigella seeds

A handful of fresh coriander leaves

Method

This classic fish curry also works well with sea bass, bream or tilapia. Mustard seeds can be bitter if overworked, so grind them only briefly in a spice grinder. Measure this powder, not the seeds, before adding it to the curry. Serve with plain boiled rice.

Marinate the fish in a quarter teaspoon of the turmeric and a good pinch of salt, tossing with your hands to coat. Meanwhile, blend the tomatoes, garlic and two or three of the green chillies (deseeded if you are worried about their heat), a little more salt, the powdered mustard seeds, remaining turmeric and 150ml water to a smooth paste.

If using mustard oil, heat 3 tablespoons in a non-stick pan until smoking, then remove from the heat and wait for 30 seconds before proceeding with the recipe. If using vegetable oil, simply heat 3 tbsp of the oil. Add the nigella seeds and,once they have sizzled for 10 seconds, put in the tomato-chilli-mustard paste. Cook over a moderate flame until all the excess moisture has evaporated and the paste releases oil, stirring occasionally. Then reduce the heat and continue cooking for four minutes or so until it darkens a little. Add 400ml water and the remaining chillies; bring to a boil and simmer for seven or eight minutes until it has a medium consistency.

Heat the remaining oil in a frying pan until smoking. Add the fish and fry well on all sides for about six minutes, until golden brown. Now put the fish in the mustard sauce, bring back to a boil and cook for two minutes. Serve with the coriander leaves.

Taken from 'I Love Curry' by Anjum Anand (Quadrille, £16.99). Photograph by Jonathan Gregson