Grilled spring onions with romesco sauce

Contributed by Benjamin Maring, MD

Grilled spring onions with romesco sauce

Breaking out the grill is a great way to celebrate the arrival of warmer weather. Inviting friends and family over makes it even more festive.

Still vivid in my mind is decade-old footage of a Catalonian calҫotada, an annual onion festival in which communities celebrate by coming together and eating plates full of grilled calҫots, a spring onion variety.

The onions are first charred on large open grills, then steamed in newspaper wraps. What emerges once the charred outer layers are removed is a tender onion heart that, dipped in romesco sauce, is a blissful combination of warmth, sweetness, richness, and spice.

This is one messy affair, so invite your gamest of friends and don’t forget the napkins.

Servings: 4, as an appetizer (with lots of romesco sauce to spare)

Prep time: 40 minutes


  • 3 ancho chilis
  • 6 plum tomatoes, cored (whole, peeled canned tomatoes work well)
  • 1 small yellow onion, peeled, trimmed, and cut into half-inch rounds
  • 3 garlic cloves, unpeeled
  • 1 red bell pepper, stemmed, seeded, and pith removed, cut into in big chunks
  • 1/4 cup almonds, blanched and toasted preferred (but raw almonds are also okay)
  • 1 slice of country bread, lightly toasted
  • 1 teaspoon sweet paprika
  • 4 teaspoons sherry vinegar
  • 3/4 teaspoon salt
  • 1/2 cup extra-virgin olive oil
  • 4 pounds spring onions, baby leeks, or thick scallions


  1. To make the romesco sauce, start by soaking the ancho chilis in boiling water for 15 minutes. Once softened, remove the stems and seeds and tear the chilis into large chunks. Reserve 1/4 cup of the soaking liquid.
  2. Preheat the broiler on high. Cover a sheet pan with aluminum foil and spread out the tomato, onion, garlic, and bell pepper in an even layer. Broil for 3 to 5 minutes, checking every so often, until the vegetables have roasted edges in places. Turn over and broil for another few minutes. Remove from the broiler and transfer to the bowl of a food processor.
  3. Add to bowl: soaked chilis, reserved soaking liquid, almonds, bread (torn into chunks), paprika, sherry vinegar, and salt. Process the mixture into a smooth paste. With the machine running, slowly drizzle in the olive oil. Taste and adjust the seasoning as desired. Let the romesco sauce hang out at room temperature for at least an hour or so before serving.
  4. Light a grill. When it is very hot, place the spring onions directly on the grill and cook, turning occasionally, until the white parts are getting tender and there are charred bits in places.
  5. Remove from the grill and wrap in newspaper to let steam for at least 15 minutes.
  6. Serve the grilled onions with romesco sauce on the side. To eat the onions, peel away any burnt layers to expose the tender heart of the onion and dip in the romesco. 

Nutrition information (per serving)

  • Calories: 340
  • Total fat: 18 g
  • Saturated fat: 2.5 g
  • Cholesterol: 0 mg
  • Sodium: 340 mg
  • Total carbohydrate: 45 g
  • Dietary fiber: 15 g
  • Total sugars: 14 g
  • Protein: 11 g