Toast the almonds in a dry pan until golden. Put the almonds, peppers, 1 small ciabatta slice (about 10g – an end piece is ideal), 1/ 2 tbsp olive oil, the vinegar, chilli, paprika , garlic and some seasoning in a food processor (or use a stick blender). Blend until smooth, then transfer to a bowl and chill in the fridge until needed. Can be done a day in advance.
Put the leeks in a saucepan and cover with water. Bring to the boil and cook for 5 mins. Drain on kitchen paper until needed.
When you’re ready to serve, heat grill to high. Put the cooked leeks on a baking tray, season and drizzle with 2 tsp olive oil. Grill the leeks until starting to blacken, about 8-10 mins, turning once during cooking.
Toast the remaining ciabatta slices and spread with a little of the romesco. Gently pull the leeks into ribbons and pile them on top. Season well and serve immediately.