Cook the onion, garlic and chilli in olive oil in a pan over a medium heat until soft, about 10 mins.
Add the leeks and celery, then cook for 5 mins.
Tip in the wine or stock and the tomatoes, reduce the heat to low and cook for 25 mins.
Add the mussels (in their shells) and prawns, cover the pan and cook for 4 mins or until the mussels are wide open (discard any that don’t open) and the prawns heated through.
Stir in the parsley and season.
Serve with garlic bread or rice.
This recipe is by Rachel Allen and is reprinted with the permission of the BBC Lifestyle channel.