Grilled leeks turn tender and lightly smoky, while romesco—a Spanish-inspired sauce of roasted red peppers, almonds, garlic, and tomato—adds tang, richness, and a little sweetness. The sauce can be made ahead, and the leeks cook quickly on a hot grill, making this a satisfying vegetable side that feels special without complicated techniques.
Ingredients
- 4 medium leeks, about 1½ pounds (680 g) total
- 2 tablespoons olive oil, divided
- ½ teaspoon kosher salt, plus more to taste
- ¼ teaspoon freshly ground black pepper
- 1 large red bell pepper
- 1 medium ripe tomato, halved, or ½ cup drained canned crushed tomatoes
- ⅓ cup (about 40 g) blanched almonds
- 1 small garlic clove, peeled
- 1 tablespoon sherry vinegar, plus more to taste
- ½ teaspoon smoked paprika
- ¼ teaspoon fine salt for the sauce, plus more to taste
- 2 to 4 tablespoons water, as needed
- 1 tablespoon chopped flat-leaf parsley, optional, for serving
Instructions
- Make the romesco. Heat the oven to 425°F (220°C). Set the red pepper on a small baking sheet and roast for 25 to 30 minutes, turning once, until softened and blistered in spots. Put it in a covered bowl for 10 minutes to steam, then peel away the skin, remove the stem and seeds, and roughly chop the flesh. It is fine if a few small pieces of skin remain.
- Toast the almonds. While the pepper roasts, toast the almonds in a dry skillet over medium heat for 3 to 5 minutes, stirring often, until fragrant and lightly golden. Transfer them to a plate so they do not continue browning in the hot pan. If using a whole fresh tomato, roast it on the same baking sheet for about 15 minutes, until soft; discard any loose skin.
- Blend the sauce. Put the pepper, tomato, almonds, garlic, sherry vinegar, smoked paprika, 1 tablespoon olive oil, and ¼ teaspoon fine salt in a food processor. Pulse until mostly smooth but still slightly textured, scraping down the bowl as needed. Add water a tablespoon at a time until the sauce is thick but spoonable. Taste and adjust the salt or vinegar. Set aside; romesco can be served cool or at room temperature.
- Prepare the leeks. Trim off the root ends and the tough, dark-green tops, leaving the pale green and white portions intact. Slice each leek lengthwise down the middle. Rinse each half thoroughly under cool running water, fanning the layers to remove trapped grit, then pat dry. Keeping the halves in one piece makes them easier to turn on the grill.
- Heat the grill. Preheat a gas or charcoal grill to medium-high, about 400°F (205°C), and clean the grates. Brush the cut sides and outer surfaces of the leeks with the remaining tablespoon of oil. Season with ½ teaspoon kosher salt and the black pepper.
- Grill until tender. Place the leeks cut-side down over direct heat. Grill for 4 to 6 minutes, until well marked, then turn and cook for another 4 to 6 minutes. Move them to a cooler part of the grill if they are browning too quickly. They are ready when the centers are tender when pierced with a knife and the outer layers are lightly charred. If the leeks are especially thick, cover the grill for a few minutes or continue cooking over indirect heat.
- Serve. Arrange the leeks on a platter and spoon romesco over or alongside them. Finish with parsley if you like, and serve with extra sauce at the table. Taste one leek and add a pinch of salt if needed.
Tips
- Clean carefully. Soil often collects between leek layers. Cut them lengthwise before rinsing, and check near the root end. Do not leave them soaking in a bowl of water, where grit can settle back onto them.
- Keep the halves intact. A small piece of root end helps the layers hold together while grilling. Trim it close, but not so close that the leek falls apart.
- Adjust the romesco texture. For a more rustic sauce, pulse briefly; for a smoother dip, blend longer and add water gradually. Almond butter can substitute for the almonds: start with 2 tablespoons and thin as needed.
- Watch the heat. Leeks contain natural sugars and can char before their centers soften. Turn them as needed and finish over indirect heat rather than letting the outside burn.
Serving Suggestions
Serve the leeks warm or at room temperature as a vegetable side with grilled chicken, fish, lamb, or chickpeas. They also work as part of a tapas-style meal alongside olives, crusty bread, and a simple salad. For a light lunch, lay the leeks over toasted bread spread with romesco, then add a fried egg or crumbled feta.
Put some sauce beneath the leeks and offer the rest separately so the charred surfaces stay visible. A squeeze of lemon or a few drops of extra sherry vinegar can brighten the finished platter, especially if the sauce tastes rich or mellow.
Variations
For a shortcut, use one 12-ounce jar of drained roasted red peppers instead of roasting a fresh pepper. The flavor will be slightly less smoky, so add an extra pinch of smoked paprika if you like. Walnuts or hazelnuts can replace the almonds in the same quantity; toast them first for better flavor.
To make the sauce dairy-free, follow the recipe as written. For a dairy-rich version, serve with a spoonful of thick yogurt or crumbled goat cheese, rather than blending it into the romesco. If you do not have a grill, use a grill pan over medium-high heat or roast the leeks cut-side up at 425°F (220°C) for about 20 to 25 minutes, turning once, until tender and browned.
Storage and Reheating
Refrigerate cooked leeks and romesco separately in airtight containers within 2 hours of cooking. They keep for up to 3 days in the refrigerator. Do not leave them at room temperature for more than 2 hours, or 1 hour if the temperature is above 90°F (32°C). Discard anything left out longer.
Reheat the leeks in a covered skillet over low heat with a teaspoon of water, or in a 350°F (175°C) oven until warmed through, about 8 to 12 minutes. A microwave also works in short bursts, though it will soften the charred exterior. Romesco is best served cool or brought to room temperature; stir it and loosen with a little water or olive oil if it has thickened. Avoid repeatedly warming and cooling the sauce.
Frequently Asked Questions
Can I make romesco ahead?
Yes. Make it up to 3 days ahead and keep it covered in the refrigerator. Its flavor often improves after a few hours. Let it sit at room temperature briefly before serving, then stir and adjust the consistency and seasoning.
Can I grill the leeks without cutting them in half?
Yes, if they are small and thoroughly cleaned, but whole leeks take longer and can cook unevenly. Halving them exposes more surface to the grill and makes it easier to check for grit and tenderness.
How do I know when the leeks are cooked?
The outside should have grill marks, and a thin knife should slide through the thickest part with little resistance. If they are still firm inside, move them away from direct heat and cook a few minutes longer.
Is romesco supposed to be completely smooth?
No. Traditional-style romesco can have a slightly coarse texture from the nuts. Blend it to suit your preference, but add water gradually so it stays thick enough to cling to the leeks.
What can I use instead of sherry vinegar?
Red wine vinegar is a good substitute. Start with the same amount, taste, and add more only if the sauce needs extra brightness. Lemon juice works in a pinch but gives the sauce a fresher, less rounded flavor.
Can I make this without an outdoor grill?
Yes. Use a ridged grill pan on the stovetop, or roast the prepared leek halves at 425°F (220°C) until tender and browned, about 20 to 25 minutes. Turn them once for more even color.