Heat the oil in a large saucepan, add the onion and cook for 7 minutes until very soft. Add the chilli and garlic and cook for a further 1 minute. Pour in the wine and cook for 2 minutes until slightly reduced, then stir in the beans and season to taste with salt.
Tip in the clams, cover and cook over a low heat for 3–5 minutes, shaking the pan occasionally, until the clams have opened. Discard any that remain closed. Serve scattered with parsley, with some crusty bread.