Classic Prawn Bisque

Heat a large, heavy-based pot over high heat until smoking. Add half the butter and, when it foams and subsides, add all the prawn shells and heads in a single layer. Press them down firmly with a wooden spoon and do not stir for 60 seconds. The shells will turn vivid coral-red and the tomalley in the heads will burst into fragrant orange fat. Stir and press repeatedly for 4–5 minutes, crushing the heads to release every drop of their orange coral. You are building the bisque's characteristic coral color and deep crustacean flavor entirely at this stage — pale, unroasted shells make a pale, insipid bisque. The pot bottom should develop a golden-orange fond.

Add the remaining butter to the pot with the roasted shells. Add the finely diced onion, celery, carrot, and garlic all at once. Sauté, stirring frequently, for 5–6 minutes until the vegetables are completely softened and beginning to turn golden — they need to be truly soft before the liquid goes in, as the short simmering time won't cook them further. Add the tomato paste and cook, pressing and stirring, for 3–4 minutes until it darkens from bright red to brick-red (the pinçage). This caramelization of the tomato paste is essential — it adds sweetness and body, and removes the harsh raw-tomato note.

Remove the pot briefly from heat. Add the cognac and tilt the pot to ignite over a gas flame, or simply return to high heat and let it reduce vigorously for 2 minutes — the alcohol must be cooked off entirely. Scrape every bit of the caramelized fond from the pot bottom with a wooden spoon. Add the white wine and reduce by half over high heat. Add the fish stock or water, bay leaves, thyme, and peppercorns. Bring to a bare simmer. Cook at a gentle simmer for exactly 25 minutes — never boil a shellfish stock hard, as bitter compounds extract from the shells beyond this point. At 25 minutes the stock should be a deep coral-amber and smell intensely of the sea.

Remove the pot from heat. Using a spider or slotted spoon, fish out and discard the bay leaves and thyme sprigs. Pour everything else — shells, vegetables, and all liquid — into a high-powered blender in batches. Blend each batch on maximum power for 60 seconds. The shells will be completely pulverized into the liquid, adding body and the maximum extraction of their flavor. Pass the blended bisque through a fine-mesh strainer set over a clean pot, pressing very firmly on the solids with the back of a ladle to extract every drop. Discard the fibrous shell remnants in the strainer. The strained bisque should be smooth, velvety, and the color of a coral sunset — no grit or shell fragments.

Return the strained bisque to a medium pot over medium heat. Add the double cream and bring to a gentle simmer. Reduce, stirring occasionally, for 5–8 minutes until the bisque coats the back of a spoon in a thin, even layer — this is the nappe consistency. Meanwhile, in a separate small pan, quickly sauté the reserved whole prawn flesh in butter for 90 seconds until just pink and cooked — do not overcook. Season the finished bisque with sea salt, white pepper, and a pinch of cayenne. Taste carefully: the bisque should taste of sweet cream and concentrated ocean, with a lingering savory finish. Ladle into warm bowls, arrange 2–3 sautéed whole prawns in the center of each bowl, and scatter the chives. Serve with crusty bread.