Drain the sauce from the mussels into a large pan and add the stock. Tip in the potatoes, cover and bring to the
boil, then remove the lid and simmer for 12 minutes, or until
the potatoes are tender.

Stir the fish and mussels into the soup, then bring back to
a simmer for 3 minutes, or until the fish has changed colour and
flakes easily. Stir in most of the parsley, then serve scattered
with the rest of the parsley and eat with crusty bread.