Heat the oil in a frying pan over a medium heat. Add the onion and garlic and fry for 5-6 minutes, or until softened and just starting to brown.
Add the dried chilli, the cockles, white wine, passata and season, to taste, with salt and freshly ground black pepper.
Cover the pan with a lid and steam the cockles for 4-5 minutes, shaking the pan occasionally, until all of the cockles have opened. Discard any cockles that have not opened after five minutes.
To serve, stir in the fresh parsley and spoon into bowls. Serve with crusty bread.
