Let leeks shine with roasted fish and olive salsa verde

I never appreciated leeks as a vegetable – as opposed to an aromatic – until I ate them with vinaigrette in Paris during my college year abroad.

At a tiny cafe that was halfway between my studio apartment near Porte Saint-Martin and my best friend’s seventh-floor walk-up near the Seine, the two of us spent our evenings drinking carafes of red wine and working our way through the very classic menu: cheesy croque-madames, herby escargots, oeufs mayonnaise.

The leeks vinaigrette was the biggest surprise. The gentle leeks looked plain on the plate – pale, monochrome, unadorned by any herbs or garnishes – but they hit us right between the eyes. They were coated in a vinaigrette with so much spicy Dijon it made our sinuses burn; we couldn’t get enough. So we added even more from the mustard pot on the table, then wiped up the oily slicks with torn bits of baguette. It gave us fortitude for the long walk home through the cold Paris night.

Back in New York, I tried to make leeks vinaigrette with as much sharpness and vim, but it was hard to match the flavour. The mustard I could get didn’t have the same piercing bite.

Instead, to mimic that play of pungent and mild, I began pairing silky leeks with other zippy condiments and sauces. Salsa verde, with its mix of citrus, minced herbs and plenty of raw garlic, was a perfect partner, balancing the sweetness of the leeks with a bracing tanginess. Leeks salsa verde became a staple in my kitchen, a lively alternative to leeks vinaigrette.

In this more substantial variation, the leeks and salsa verde are rounded out with quick-cooking fish fillets.

I particularly like the mellowness of white fillets like cod, halibut or hake here, as they can really soak up the complexity and brightness of the salsa verde. But salmon or tuna would also work, lending more richness to the mix.

To make this as weeknight friendly as possible, I roast the fish and leeks together in one pan. As they cook, the leeks closest to the fillets absorb their liquid, turning soft and plush while the ones near the edges of the pan get pleasingly brown and crisp in spots.

Topped with an olive-spiked salsa verde, it is a dish both mellow and robust, where those sweet, overwintered leeks of spring can really shine.

Roasted fish with leeks and olive salsa verde

By: Melissa Clark

Serves: 4

Total time: 30 minutes

Ingredients:

For the fish and leeks:

4 thick fillets white fish, such as cod or halibut (about 680g total)

Salt and freshly ground black pepper

3 medium leeks, trimmed, white and light green parts halved lengthwise and rinsed well

Extra-virgin olive oil

For the olive salsa verde:

1 lemon

90g coarsely chopped pitted Castelvetrano olives

10g chopped coriander leaves and tender stems

1 garlic clove, finely grated, minced or pushed through a garlic press

Large pinch of red-pepper flakes, or to taste

Fine sea or table salt

80ml extra-virgin olive oil

Method:

1. Heat oven to 220C. Season fish all over with salt and pepper, and set aside while you prepare the leeks.

2. Cut the leeks into matchsticks: place a leek half, flat side down, on a cutting board and cut it in half crosswise. Then slice the pieces lengthwise into thin (½cm-thick) matchsticks. Repeat with remaining leeks.

3. Spread leeks out on a rimmed baking tray. Lightly drizzle them with oil and a pinch of salt and pepper, and toss to coat. Push aside the leeks to create 4 spaces in the center of the sheet pan just large enough for the fish fillets, then place the fillets in those cleared spaces (avoid putting the fish on top of the leeks, which won’t cook as well if they’re covered).

4. Drizzle fish with oil. Roast until the fish is opaque and just cooked through but not yet flaky, about 10 to 15 minutes, depending on the thickness of fish. The leeks surrounding the fish will be soft and silky, while those at the edges of the pan may turn delightfully brown and crisp in spots. If the fish is done but you think the leeks need a little more time, transfer the fish to a serving platter, tent with foil to keep warm, and continue to cook the leeks for another few minutes.

5. While the fish is in the oven, make the salsa verde: using a fine rasp grater, grate ½ teaspoon lemon zest into a small bowl. Halve the lemon and squeeze in 1 tablespoon juice.

6. Stir in olives, cilantro, garlic, red-pepper flakes and a pinch of salt. Slowly drizzle in oil, stirring to combine. Taste and add more salt, red-pepper flakes or another squeeze of lemon, if needed.

7. Place fish on plates and surround with leeks. Top with olive salsa verde.

And to drink...

White fish, like halibut and cod, tend to be neutral vehicles for accompanying sauces and other flavourings. In this recipe, that includes the sweet-savoury leeks and the zesty salsa verde. Both call for crisp white wines that are not oaky, with the lively acidity to cut through and complement the olives in the sauce. That would include Loire sauvignon blancs with herbal and citrus flavors rather than the more flamboyant New Zealand style, village Chablis or other restrained chardannays, and good albariños from northwestern Spain. You could also try a Corsican vermentinu, many good Italian whites and maybe even a grüner veltliner from Austria. If you have the taste for sherry, try a fino or manzanilla, which are made to go with olives and seafood.

Pairings by Eric Asimov.

© The New York Times