Chilled Romano pepper soup

Heat the oil in a large saucepan. Add the onions, celery and bay leaves. Cook for 8 minutes over a medium heat until the onions have softened, then add the peppers and cook for 10 minutes more, turning up the heat so the peppers fry.

Stir in the cumin, paprika and tomatoes; simmer for 8-10 minutes, stirring occasionally, then add the stock and cook for a further 5 minutes. Remove and discard the bay leaves, then add the salt, vinegar and most of the coriander leaves (reserve some for serving). Whizz with a hand blender (or in batches in a jug blender) until smooth. Leave to cool, then cover and chill (ideally overnight). Serve chilled, in bowls, with a dollop of yogurt on top, a sprinkling of nigella seeds and the remaining coriander leaves scattered over.