Steps
1. Preheat your grill on medium-high heat.
2. Place the red bell pepper and garlic cloves (with skins on) on the grill. Roast until the pepper is charred and the garlic is soft, about 10-15 minutes.
3. While the peppers are roasting, wash the calçots and trim the roots. Grill them for about 8-10 minutes, turning occasionally, until they are tender and slightly charred.
4. Once the pepper is charred, remove it from the grill, peel off the skin, and remove the seeds. Let the garlic cool, then squeeze the cloves out of their skins.
5. In a blender or food processor, combine the roasted red pepper, garlic, almonds, hazelnuts, olive oil, vinegar, salt, and pepper. Blend until smooth, adding a little water if necessary to reach the desired consistency.
6. Serve the grilled calçots hot, drizzled with the romesco sauce and garnished with fresh parsley if desired.