Heat the oil in a large saucepan, add the onion and cook over low heat for 5 minutes or until softened.
Stir in the garlic and paprika, cook for one minute, then add the tomatoes and stock. Bring to the boil, then reduce the heat and simmer for 10 minutes, stirring occasionally.
Add the fish, prawns and mussels and simmer for about 5 minutes or until the fish is just tender and the mussels have opened.
Stir in the parsley and season to taste with salt and pepper.
Serving Suggestions: Serve with crusty bread and butter.