Olive Oil-Poached Tuna Confit

Pat the tuna steaks completely dry with kitchen paper. Season all surfaces evenly with the flaky sea salt, cracked black pepper and crushed coriander seeds.

Transfer the seasoned tuna to a plate, cover loosely, and refrigerate uncovered for 1 hour to allow the seasoning to penetrate and the surface to dry further.

Remove the tuna from the refrigerator and allow it to sit at room temperature for 20 minutes so the fish warms slightly and will cook evenly.

Choose a heavy-based saucepan or deep sauté pan just wide enough to hold the tuna steaks snugly in a single layer. Add the olive oil, thyme, rosemary, garlic, bay leaves, shallot rings, lemon zest, orange zest and chilli flakes. Set over the lowest possible heat and warm the oil, monitoring with an instant-read thermometer, until it reaches 60°C — this will take approximately 10–12 minutes.

Gently lower the tuna steaks into the aromatic oil, ensuring they are fully submerged; add a little more olive oil if needed. Maintain the oil temperature strictly between 60–65°C throughout cooking, adjusting the burner as needed and checking with a thermometer every few minutes.

Poach the tuna for 30–35 minutes until an instant-read thermometer inserted into the thickest part reads 63°C and the flesh is opaque throughout yet still yields gently when pressed.

Using a slotted spoon or fish spatula, carefully lift the tuna from the oil and transfer to a warm plate. Spoon over a few tablespoons of the aromatic poaching oil, scatter the capers over the fish, and rest for 2 minutes before serving.

Serve each piece of tuna on or alongside grilled sourdough with lemon wedges, and offer the remaining strained poaching oil at the table for drizzling.