Steps
1. Heat the olive oil in a pot over medium heat.
2. Add the diced onion and garlic, sauté until translucent.
3. Stir in the chopped tomato, carrot, and celery; cook for 5 minutes.
4. Pour in the white wine and let it simmer for 2 minutes to evaporate the alcohol.
5. Add the fish stock and bring the mixture to a boil.
6. Reduce the heat, add the fish, dried oregano, salt, and pepper.
7. Simmer for about 10 minutes, until the fish is cooked through.
8. Serve hot, garnished with fresh parsley.