Roast Salmon With Leeks Onions

The smell of roasted leeks hit me before I even opened the oven, sweet and soft, mingling with the richness of salmon skin crisping at the edges. I was testing this recipe on a cold Tuesday, craving something that felt nourishing without demanding much from me. The parsley dressing came together while I waited, bright green and sharp, and when I spooned it over the golden fillets, I knew I'd be making this again and again. It's the kind of meal that feels elegant but forgives distraction, which is exactly what I needed that night.

I made this for friends who arrived tired and hungry after a long drive, and I watched their faces soften as they took the first bite. The leeks had gone jammy and sweet, the onions caramelized at the tips, and the dressing pulled everything together with its bright, briny kick. One of them asked for the recipe before she even finished her plate. That's when I knew it wasn't just easy, it was the kind of dish that makes people feel cared for without you having to fuss.

Ingredients

• Salmon fillets (skin-on): The skin protects the delicate flesh and crisps beautifully against the hot pan, adding texture and helping the fish stay moist.
• Leeks: Slice them into thick rounds so they hold their shape and develop a tender, almost buttery sweetness as they roast.
• Red onion: Cut into wedges rather than thin slices; they caramelize without burning and add a mild, roasted depth.
• Olive oil: Use enough to coat the vegetables well, this helps them brown and prevents sticking.
• Lemon slices: They char slightly in the oven and release their juice over the salmon, brightening every bite.
• Fresh flat-leaf parsley: The star of the dressing, it should be vibrant and finely chopped for maximum flavor and color.
• Garlic: Just one small clove is enough, it sharpens the dressing without overpowering the parsley.
• Dijon mustard: Adds body and a subtle tang that ties the dressing together.
• Capers: Briny and punchy, they bring a savory pop that balances the richness of the salmon.
• Lemon zest and juice: Fresh citrus makes the dressing sing, use both for brightness and aroma.

Instructions

Preheat and Prep:

Set your oven to 400°F (200°C) and let it come to temperature while you slice the leeks and onion. This gives the vegetables a head start and ensures even roasting.

Roast the Vegetables First:

Spread the leeks and red onion on a large baking sheet, drizzle with olive oil, season with salt and pepper, and toss until everything glistens. Roast for 10 minutes so they begin to soften and sweeten before the salmon joins them.

Nestle the Salmon:

Pull the sheet from the oven and tuck the salmon fillets skin-side down among the vegetables, then lay lemon slices over the top. The fish will cook quickly, so don't skip this step or it may end up overdone.

Finish Roasting:

Return the pan to the oven and roast for 12 to 15 minutes, until the salmon is just opaque in the center and flakes gently with a fork. The vegetables should be tender and beginning to brown at the edges.

Make the Parsley Dressing:

While the salmon roasts, combine parsley, garlic, Dijon mustard, capers, lemon zest, olive oil, and lemon juice in a small bowl. Stir well, taste, and adjust the seasoning with salt and pepper.

Plate and Dress:

Transfer the salmon and vegetables to plates, then spoon the bright parsley dressing generously over each fillet. Serve immediately while everything is warm and fragrant.

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The first time I drizzled that parsley dressing over the salmon, I stood at the counter and ate a forkful straight from the pan. It was bright, rich, and somehow comforting all at once, the kind of flavor that makes you close your eyes for a second. I realized then that this wasn't just dinner, it was the kind of meal that resets your week.

Choosing Your Salmon

I always look for fillets that are firm to the touch, with skin that's intact and shiny. Wild-caught salmon has a deeper flavor, but farmed works beautifully too, especially if you're watching your budget. If the fillets are uneven in thickness, tuck the thinner tail ends under slightly so they don't overcook. Ask your fishmonger to remove any pin bones, or run your fingers along the flesh and pull them out yourself with tweezers.

Making It Your Own

I've swapped the salmon for thick cod fillets when that's what I had, and the timing stayed nearly the same. You can add halved cherry tomatoes to the vegetables for extra sweetness, or toss in a handful of olives if you love briny flavors. Some nights I stir a spoonful of Greek yogurt into the dressing to make it creamy, and it's just as good. The beauty of this recipe is that it bends without breaking.

Serving and Storing

This dish is perfect with roasted potatoes, steamed rice, or even a simple green salad on the side. Leftovers keep well in the fridge for up to two days; reheat gently in a low oven to avoid drying out the salmon. The parsley dressing can be made a day ahead and stored in a jar, just give it a good stir before spooning it over the fish.

• Serve with crusty bread to soak up the dressing and vegetable juices.
• Double the dressing recipe and use leftovers on grilled chicken or roasted vegetables.
• If reheating, cover the salmon loosely with foil to keep it moist.

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This is the kind of recipe I return to when I want something that feels special without the stress. It reminds me that good food doesn't have to be complicated, just thoughtful and made with care.

Frequently Asked Recipe Questions

→ Can I use frozen salmon fillets?

Yes, but ensure they are fully thawed and patted dry before roasting to achieve the best texture and even cooking.

→ What can I substitute for leeks?

You can use fennel bulb slices or additional onions. Shallots also work well and provide a milder, sweeter flavor.

→ How do I know when the salmon is cooked through?

The salmon should flake easily with a fork and register 145°F (63°C) internally. It should appear opaque throughout with a slightly pink center.

→ Can I make the parsley dressing ahead of time?

Absolutely. Prepare the dressing up to 2 days in advance and store it covered in the refrigerator. Stir well before serving.

→ What other fish works well with this preparation?

Trout, Arctic char, cod, or halibut are excellent alternatives. Adjust cooking time based on thickness—thicker fillets need a few extra minutes.

→ How should I store leftovers?

Store cooked salmon and vegetables separately from the dressing in airtight containers for up to 2 days. Reheat gently to avoid drying out the fish.