Preheat your oven to 220°C/Gas 8. Place a baking tray on the top shelf to heat up. As soon as it’s hot, place your pepper in the oven, on the tray. Roast till charred on both sides, about 30 mins, turning it half way through.
Finely chop your onion, celery and garlic (washing and peeling them first, of course). Get a large pot or frying pan hot. Add a gloss of oil. Swirl in the chopped veg. Sizzle over medium low heat till glossy and tender.
Fold the paprika through. Drain your beans. Add them. Fill the empty tin with water. Pour it in. Let it gently bubble away till your pepper is done.
Let your pepper cool a little. Pull the stock out. Strip the skin from it. Scrape or rinse the seeds off. Finely chop the flesh of pepper. Swirl it through the soup.
Bring the heat up to a gently boil. Cook just long enough to let the peppers meld into the soup. Taste. Season as needed. Add more paprika, if you like.
Finish with a little clementine zest and juice. Splendid.