Heat the olive oil in a soup pot over medium heat. Add the celery, potatoes and onion and cook, stirring occasionally, for 2-3 minutes. Add the garlic, basil, parsley and red pepper flakes and cook for about one minute, stirring constantly. Stir in the tomato paste. Add the tomatoes, fish stock and white wine. Bring to a simmer, lower the heat, cover the pan and simmer for about 30 minutes. Add the fish, cover the pan and cook for 6-8 minutes. Taste for seasoning and season with salt and pepper to taste.