Cider-Braised Pollack with Shallots and Crème Fraîche

Preheat the oven to 160°C (fan 140°C or 325°F). Pat the pollack fillets dry with kitchen paper and season on both sides with the sea salt and white pepper. Slice the shallots, garlic and leek. Slice the mushrooms. Measure out the cider and fish stock.

Set a wide, ovenproof sauté pan or shallow casserole over medium heat and melt the butter until it foams. Add the shallots and leek and cook, stirring occasionally, until softened and translucent, about 8 minutes. Do not let them colour.

Add the garlic and mushrooms to the pan and cook, stirring, until the mushrooms release their liquid and it evaporates, about 5 minutes.

Pour in the cider and raise the heat to medium-high. Bring to a vigorous simmer and cook, uncovered, until reduced by one third, about 8 minutes. Add the fish stock, thyme sprigs and bay leaves.

Nestle the seasoned pollack fillets skin-side down into the braising liquid. The liquid should come halfway up the sides of the fillets. Slide the pan into the preheated oven.

Braise in the oven until the fillets reach an internal temperature of 63°C — check with a meat thermometer after 12 minutes. The flesh should be just opaque and yield easily to gentle pressure.

Using a wide spatula, carefully lift the fillets out of the pan and transfer to a warm plate. Cover loosely with foil to rest while you finish the sauce.

Remove the thyme and bay leaves. Place the pan over medium-high heat and bring the braising liquid to a brisk simmer. Cook until reduced by half, about 5 minutes.

Reduce the heat to low. Stir in the crème fraîche and Dijon mustard and simmer gently, stirring, until the sauce coats the back of a spoon, about 3 minutes. Do not boil vigorously once the crème fraîche is added or the sauce may split.

Add the lemon juice, taste and adjust seasoning. Return the fillets to the pan skin-side up, spoon the sauce over them, and scatter with the chopped parsley. Serve immediately with steamed new potatoes or crusty sourdough to mop the sauce.