A light Bengali fish curry of sea bass steaks and potato in a turmeric-and-mustard gravy, scented with nigella and bay. It tastes gently spicy, mustardy and turmeric-forward.
Ground spices for fish and sauce
8 gHalf the turmeric rubbed on the fish (step 1); the rest with coriander into the sauce (step 5)
Rub 550 g sea bass steaks with half of the 3 g ground turmeric from the ground spices for fish and sauce and a pinch of the 0.3 g salt. Leave aside.
Blend 12 g garlic, 5 g ginger and a splash of water to a paste.
Heat 40.5 g vegetable oil in a heavy saucepan over medium heat. Add the whole spices for the oil and fry until they crackle.
Add 4 g green bird's-eye chilli, pricked, and the garlic-ginger paste. Fry for 1 minute.
Add 150 g tomato and cook for 5–6 minutes, stirring, until softened. Stir in the ground spices for fish and sauce: the remaining turmeric and 5.4 g ground coriander.
Add 270 g potato and fry for 2 minutes.
Pour in 497 g water and add salt to taste. Cover and simmer over low heat for 20 minutes, stirring now and then.
Add the fish steaks and stir gently. Cover and simmer for 3–4 minutes, until the fish is cooked through.
Mix in 7.5 g English mustard, loosened with a splash of water, and the finishing spice. Simmer for 1 minute.
Turn off the heat and scatter over 1.5 g chopped coriander to garnish.
Steep a tiny pinch (0.1 g per 2 g turmeric) in 2 tbsp warm water; use to match the rich golden hue. Contributes an aristocratic, honeyed floral flavour rather than earthy bitterness.
Use 15% to 20% of the weight (about 1 g for every 5 to 6 g fresh cloves). Whisk into sauces; gives a savoury, toasted garlic flavour without raw pungency.
Use 20% to 25% of the weight (1 g for every 4 to 5 g fresh). Stir into the gravy; adds peppery heat and warmth, though it misses the crisp, zesty kick of raw root.
Use 40% to 50% of the fresh tomato weight mixed with a splash of water. Imparts a deeper red colour, thicker sauce, and slightly sweeter cooked flavour.
Use 50% of the weight and stir in near the end of cooking. Adds warmth and depth since it contains ground coriander, but introduces stronger spices like clove and cinnamon.
Use 50% of the weight mixed with equal parts ground coriander and a pinch of ground cinnamon, ground cloves, and ground green cardamom. Sprinkle near the end for a warming finish.