Buttered Salmon with Red Onion, Capers and Dill

Preheat the oven to 325° F (163° C). Thinly slice half the lemon and remove any seeds; save the other half for juicing.

Place the salmon skin side down on a baking sheet or in a large baking dish and season with salt and pepper.

Heat the butter in a medium skillet over medium-high heat. Cook, swirling occasionally, until the butter has started to brown, 2-3 minutes. Add the olive oil, sliced lemon and half the onion. Season with salt and pepper and cook, tossing occasionally, until the lemon and onion have started to brown and frizzle, 2-3 minutes (you’re looking for a kind of crisped rather than softened and caramelized). Add the capers and let them pop and fry a minute or two.

Pour the brown butter-lemon mixture over the salmon. Place it in the oven and roast until just cooked through but still medium rare inside, 12-15 minutes; the flesh will more translucent, less opaque. Remove from the oven and transfer to a serving dish.

Meanwhile, toss together the dill and sesame seeds, if using, in a medium bowl. Give a squeeze from the halved lemon and season with salt and pepper. Scatter on top of the salmon, along with the remaining sliced onion.