Salmon with Leeks and Onions

My kitchen smelled like garlic and lemon, and I was staring at a single dirty sheet pan in the sink. That was the moment I realized this salmon recipe had just saved my Tuesday night. I'd been skeptical about one-pan dinners before, convinced they sacrificed flavor for convenience, but the caramelized leeks clinging to the edges of that tray told a different story. The fish had come out tender, the vegetables sweet and soft, and I hadn't even broken a sweat.

I made this for my sister when she came over after a long shift at the hospital. She sat at the counter, exhausted, and I slid a plate in front of her without much fanfare. She took one bite, paused, and asked if I'd been taking cooking classes. I hadn't, but I didn't tell her how easy it actually was. Sometimes it's nice to let people think you worked harder than you did.

Ingredients

• Salmon fillets, skin-on: The skin protects the delicate flesh from drying out and crisps up beautifully if you sear it afterward in a hot pan.
• Leeks: They turn golden and sweet when roasted, much milder than raw, and their layers soak up all the olive oil and seasoning.
• Red onion: Adds a slight sharpness that mellows into caramelized sweetness under high heat.
• Olive oil: Use a good one for drizzling over the vegetables, it makes a noticeable difference in flavor.
• Lemon slices: They roast right on top of the fish, infusing it with citrus without any squeezing or juicing required.
• Fresh flat-leaf parsley: The backbone of the dressing, it brings freshness and color that cuts through the richness of the salmon.
• Garlic clove: Just one small clove is enough to add depth without overpowering the delicate herb notes.
• Dijon mustard: It emulsifies the dressing and adds a subtle tang that ties everything together.
• Capers: Briny and bold, they give the dressing a savory punch that makes each bite more interesting.
• Lemon zest and juice: The zest is where the aromatic oils live, and the juice brings acidity that balances the richness of the olive oil.

Instructions

Preheat and Prep:

Set your oven to 400°F and let it heat fully while you slice the leeks and onion. This ensures everything starts roasting at the right temperature from the first minute.

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 them until every piece glistens. Roast them alone for 10 minutes so they get a head start on caramelizing before the salmon goes in.

Add the Salmon:

Nestle the salmon fillets skin-side down right into the vegetables, then lay lemon slices over the top of each fillet. Return the pan to the oven and roast for 12 to 15 minutes, until the salmon flakes easily and the vegetables are tender and golden at the edges.

Make the Parsley Dressing:

While the fish bakes, combine parsley, minced garlic, Dijon mustard, capers, lemon zest, olive oil, and lemon juice in a small bowl. Stir it all together, taste it, and adjust the salt and pepper until it sings.

Plate and Serve:

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

Save

The first time I served this at a small dinner party, someone asked for the recipe before they'd even finished eating. I scribbled it on a napkin, and later that week she texted me a photo of her own version with a caption that just said, why have I been overthinking dinner. That's when I knew this recipe was a keeper, not because it was fancy, but because it made cooking feel easy again.

How to Pick the Best Salmon

Look for fillets that are firm to the touch, with bright, moist flesh and no strong fishy smell. If you're buying skin-on, the skin should be shiny and intact, not dull or peeling. Wild-caught salmon has a deeper flavor, but farmed salmon works beautifully here too and tends to be more affordable. I usually ask the fishmonger what came in that morning and go with whatever looks freshest.

What to Serve Alongside

This dish is complete on its own, but sometimes I'll add a simple grain like quinoa or farro to soak up the parsley dressing. Roasted baby potatoes are another favorite, especially if you toss them on the same sheet pan halfway through the vegetable roasting time. A crisp green salad with a light vinaigrette balances the richness and keeps the meal feeling fresh and bright.

Storage and Reheating Tips

Leftovers keep well in an airtight container in the fridge for up to two days. I like to eat the salmon cold, flaked over a salad, because reheating it can make it dry. If you do reheat, use a low oven (around 275°F) and cover the fish loosely with foil to keep moisture in.

• Store the parsley dressing separately so it stays vibrant and doesn't make the fish soggy.
• The roasted vegetables reheat beautifully in a skillet over medium heat with a drizzle of olive oil.
• If the salmon seems dry after storing, a spoonful of extra dressing or a squeeze of fresh lemon revives it instantly.

Save

This recipe taught me that simple doesn't have to mean boring, and that sometimes the best meals are the ones that don't ask much of you. I hope it becomes one of those easy favorites you reach for on busy nights when you still want something that feels like care on a plate.

Recipe FAQs

→ Can I use frozen salmon fillets?

Yes, just ensure they're completely thawed and patted dry before roasting for the best texture and even cooking.

→ What other vegetables work well with this dish?

Fennel, asparagus, cherry tomatoes, or bell peppers make excellent additions or substitutions for the leeks and onions.

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

The salmon should flake easily with a fork and reach an internal temperature of 145°F. It should be opaque throughout with a slightly translucent center if you prefer it medium.

→ Can I make the parsley dressing ahead of time?

Absolutely. The dressing can be prepared up to 2 days in advance and stored in an airtight container in the refrigerator. Stir well before serving.

→ Is this dish suitable for meal prep?

Yes, the salmon and vegetables reheat well. Store components separately and add fresh dressing when serving for the best flavor and texture.

→ What can I serve alongside this salmon?

Roasted potatoes, steamed rice, quinoa, or a simple green salad complement this dish beautifully without overwhelming the delicate flavors.