Duck Parmentier

Pat the duck legs completely dry with kitchen paper. Season all over with salt, pepper, and fresh thyme leaves. Finely dice the onion, carrots, and celery, and mince the garlic.

Place the seasoned duck legs on a wire rack set over a tray, uncovered, and refrigerate for 12-24 hours to dry-brine.

Remove the duck legs from the refrigerator 30 minutes before cooking. Heat the neutral oil in a wide, heavy-based oven-safe casserole over medium heat. Lay the duck legs skin-side down and cook for 10-12 minutes until the skin is deep mahogany and the fat has rendered freely — do not move them. Flip and sear the flesh side for 3 minutes, then transfer the legs to a plate.

Preheat the oven to 160°C or 325°F, or gas mark 3. Pour off all but 2 tbsp of fat from the casserole, reserving the excess fat. Add the onion, carrot, and celery to the pot over medium-low heat and cook, stirring occasionally, for 8-10 minutes until softened and lightly golden.

Add the garlic and tomato purée to the vegetables and stir for 2 minutes until the purée darkens slightly and smells toasty.

Pour in the white wine and scrape up any browned bits from the base of the pot. Allow to bubble for 3 minutes until reduced by half.

Return the duck legs to the casserole skin-side up. Pour over the chicken stock, add the bay leaves and thyme sprigs — the liquid should come halfway up the legs. Bring to a gentle simmer, then cover with a tight-fitting lid and transfer to the oven. Braise for 2 hours 30 minutes until the meat is completely tender and pulling away from the bone — it should shred with no resistance, and a meat thermometer inserted into the thickest part of the leg should read at least 90°C. Braised confit-style duck needs this higher temperature for full collagen breakdown, well above the 74°C safe-minimum for a whole roasted poultry cut.

Transfer the duck legs to a board and allow to cool enough to handle. Strain the braising liquid into a small saucepan, discarding the spent vegetables and herbs. Skim 3 tbsp of duck fat from the surface and reserve. Simmer the remaining liquid over medium-high heat for 8-10 minutes until reduced to a glossy, lightly coating sauce.

Shred the duck meat from the bones, discarding the skin and any cartilage. Mix the shredded meat with 4-5 tbsp of the reduced sauce until it is moist and cohesive but not wet. Stir in the chopped parsley. Taste and adjust seasoning.

Boil the potato chunks in well-salted water over high heat for 20-22 minutes until completely tender when pierced with a skewer.

Drain the potatoes thoroughly, then pass them through a potato ricer or fine-mesh drum sieve back into the warm pan. Place the pan over very low heat and stir for 1-2 minutes to drive off excess moisture. Beat the cold butter into the riced potato a few cubes at a time until fully incorporated. Stir in the warm milk followed by the 3 tbsp reserved duck fat. Season generously with salt and white pepper. The purée should be rich, smooth, and just hold its shape.

Preheat the grill to high. Spoon the shredded duck filling into the base of a 30 cm gratin dish or four individual dishes, pressing into an even layer. Spoon or pipe the pommes purée over the top, covering the duck completely, then drag the back of a fork across the surface to create ridges. Scatter the grated Gruyère evenly over the top.

Place the gratin dish under the hot grill for 8-10 minutes until the surface is bubbling at the edges, the cheese is melted, and the peaks are deep golden brown. Rest for 5 minutes before serving.