Pan-fried Halibut, Fish Head Curry

1. CURRY PASTE & SAUCE BASE (make first; can rest 1 hour)
Drain the soaked dried Kashmiri chillies, reserving 2 tablespoons of the soaking water. In a pestle and mortar (or small processor), pound the lemongrass, galangal, shallots, garlic, fresh red chillies, soaked dried chillies and turmeric to a coarse paste, adding the reserved chilli water to loosen if needed. Rest at room temperature for 30 minutes to 1 hour — the flavours marry.

2. BUILD THE CURRY SAUCE
Heat 3 tablespoons of neutral oil in a wide, heavy-based pan over medium heat. Add the mustard seeds; when they pop (15–20 seconds), add the fenugreek and 12–15 fresh curry leaves and stand back — they will spit. Tip in the curry paste and fry, stirring continuously, for 8–10 minutes until the oil splits at the edges and the paste is several shades darker. This stage is non-negotiable: undercooked paste reads as raw spice. Add the fish heads and bones, turn to coat, and cook for 2 minutes. Pour in the fish stock, bring to a simmer, and cook 15 minutes. Add the coconut milk, tamarind paste and palm sugar; simmer a further 10 minutes. Do not season with fish sauce, salt or lime yet.

3. STRAIN
Pass the sauce through a fine sieve into a clean saucepan, pressing firmly with the back of a ladle to extract every drop. Discard the solids. Reduce gently if the sauce is thinner than double cream — you want a coating consistency. Cover and set aside. Final seasoning happens at the pass.

4. STUFFING FOR THE BATTERED CHILLIES
Boil the diced potato in well-salted water for 8–10 minutes until just tender; drain and spread on a tray to dry. In a small pan, warm 1 tablespoon of oil; add the mustard seeds, allow to pop, then add the torn curry leaves and the toasted desiccated coconut. Stir 30 seconds to bloom, then tip into a bowl with the potato. Crush coarsely with a fork — it should hold together but still have texture. Fold in the chopped coriander, mint, lime juice and salt to taste. Cool.

5. PREPARE THE CHILLIES
Working with each chilli on its side, slit lengthways down one edge from just below the stem to the tip, leaving the stem intact. Using a small spoon or paring knife, scrape out the seeds and ribs. Pipe or press the cooled stuffing into the cavity, gently pressing the slit closed. The chillies can sit, covered, in the fridge for up to 4 hours.

6. SAMBAL
Combine the diced cucumber, green-mango julienne, sliced banana shallot, sambal oelek, lime juice, palm sugar and (if using) fish sauce in a bowl. Stir, taste, adjust. Fold in the chopped coriander just before serving so it stays bright. The sambal lifts in the fridge for up to one hour, then begins to weep — dress it close to service.

7. FRIED OKRA & AUBERGINE
Heat 1/2 cup neutral oil in a heavy frying pan over medium-high heat. Toss the okra and aubergine with a pinch of turmeric and a little salt. Fry the aubergine first, cut-side down, 3–4 minutes until deeply golden; flip and cook 1–2 minutes. Transfer to kitchen paper. Repeat with the okra, cut-side down, 2–3 minutes until just blistered and bright green. Season with flaky salt; keep warm in a low oven.

8. TEMPURA
Bring the deep-frying oil to 170–175°C (340–350°F). Whisk the plain flour, cornflour, rice flour and salt in a bowl. Just before frying, whisk in the ice-cold sparkling water until you have a thin, lumpy batter — do not over-mix; lumps are good. Dip each stuffed chilli, allow excess to drip, and lower into the oil. Fry 2–3 minutes, turning once, until the batter is set and pale golden — not deep brown. Drain on a rack.

9. HALIBUT (last; cook to order)
Bring the halibut portions to room temperature, pat dry, and season the flesh sides lightly with salt. Heat 1 tablespoon of oil in a heavy pan over medium-high heat. Place the halibut presentation-side down and press flat with a fish slice for the first 20 seconds — this prevents curling and gives an even crust. Cook 2–3 minutes (depending on thickness) until the underside is burnished gold. Add the cold butter and the curry leaves; tilt the pan and baste the fish for 30–40 seconds. Flip, basting once or twice more. Total cooking time should be 4 minutes for a 2cm-thick fillet; pull at 50°C internal and rest 1 minute — carryover will take it to 52–54°C, which is where halibut is at its best.

10. SEASON THE SAUCE; PLATE
Warm the strained sauce gently. Now — and only now — add fish sauce a few drops at a time, then squeeze in lime to balance, tasting as you go. The sauce should be salty, sour, sweet, fragrant. Spoon a generous puddle of sauce slightly off-centre on each warm bowl. Place the rested halibut presentation-side up on the sauce. Lean the tempura chilli against the fish at an angle. Place a quenelle (or neat spoonful) of sambal beside, then arrange the fried aubergine and okra. Dot lime-leaf oil around the rim. Finish with micro purple shiso and a pinch of toasted coconut. Serve immediately.

CHEF'S NOTES
Wider, not deeper: use a wide, shallow pan for the sauce — thin proteins want thin pools of sauce, served in shallow bowls.
Strain, then season at the pass: hold salt, fish sauce and lime back; commit at service. A sauce reduced and seasoned in advance will overshoot when re-warmed.
Pale-gold tempura, not blond: keep the oil at 170–175°C and pull the chilli when the batter has set and just turned the colour of clotted cream.
Fish bones matter; halibut bones aren't enough: supplement with snapper, sea bream or cod heads — they carry the gelatinous body that traditional Singaporean and Malaysian fish-head curries depend on. Avoid oily fish (salmon, mackerel) here — the curry will read muddy.