Steps
1. Heat the olive oil in a large pot over medium heat.
2. Add the onion and garlic and cook until the onion is softened, about 5 minutes.
3. Add the tomato paste and cook for another 2 minutes.
4. Add the fish stock, potatoes, carrots, celery, and white wine.
5. Bring the soup to a boil, then reduce the heat to low and simmer for 15 minutes.
6. Add the fish and cook for another 5 minutes, or until the fish is cooked through.
7. Add the parsley, salt, and pepper and stir to combine.
8. Serve the soup hot with crusty bread.