Salmon poached in butter with green pepper, horseradish and dill

• Preheat the oven to 165 °C. Cut half of the lemon into thin slices and remove the seeds. Keep the other half for juicing.
• Boil the potatoes in well-salted water.
• Place the salmon on a rimmed baking tray or in a large baking dish (not much larger than the salmon) and season generously with salt and freshly ground black pepper.
• Heat the butter in a medium frying pan over a medium to high heat. Whisk occasionally until the butter turns hazelnut brown; 2 to 3 minutes. Add the olive oil, sliced lemon and red onion. Season with salt and pepper and fry, tossing occasionally, until the lemons and onion begin to brown; 2 to 3 minutes. Add the peppercorns (note: may splatter a little).
• Pour the browned butter and lemon mixture over the salmon. Place in the oven and roast for about 15 minutes until the salmon is just cooked through and still medium rare on the inside. The thicker part will always be less cooked than the thinner part, which is closer to the tail. Remove from the oven.
• When the potatoes are cooked, drain them and mash them a little. Arrange the salmon on a large platter, remove the skin and cut the fish into larger pieces. Serve with the potatoes and spread the butter with onions, peppercorns and lemons around the fish. Garnish with a generous pinch of freshly grated horseradish, a dollop of sour cream and dill. Sprinkle everything with the other half of the lemon. Sprinkle with flaky sea salt and season with black pepper.

* The skin keeps the salmon in one piece during cooking and makes it easier to remove. After cooking, the skin can be easily peeled off. It is also a natural protective layer between the fish and the heat source, and as it is usually greasy, it does not stick to the bottom of the pan.