This very typical Catalan sauce, which always makes an appearance whenever and wherever calçots are served, works wonders with lots of dishes, especially fish. It is made in the style of a mayonnaise, with garlic, tomato, dried nora chile, almonds, hazelnuts, extra-virgin olive oil, vinegar, salt and paprika. The secret to the perfect romesco sauce? Slowly add the ingredients to the mortar one by one, starting with the hardest, crush them with the pestle and then leave for a few hours in the fridge before serving.