1. Heat oil over medium heat in a large pot. Add onion, and sauée 5 minutes or until softened. Add garlic, and sauté 1 minute. Add olives and next 5 ingredients; bring to a boil. Partially cover, reduce heat, and simmer 10 minutes.
2. Add fish, cover, and simmer 5 to 10 minutes or until fish is opaque and flakes with a fork. Season with salt and pepper.
3. Spread baguette slices with Garlic Aïoli.
4. Ladle soup into bowls. Garnish, if desired. Dollop remaining Garlic Aïoli on soup, if desired. Serve with baguette slices.