Bring 4 cups water to a boil in large saucepan over high heat. Place tomatoes in water for 10 seconds. With slotted spoon, remove tomatoes from water; set aside to cool.
Place eggplant cubes in water in saucepan; cover and simmer 10 minutes. Drain; set eggplant aside.
Wipe saucepan dry with paper towels. Heat oil in saucepan over medium heat until hot. Add onion; cook 5 minutes, stirring frequently.
Meanwhile, remove and discard skins from tomatoes; coarsely chop tomatoes.
Add tomatoes, eggplant, garlic, basil, sugar, salt and vinegar to onion in saucepan; mix well. Cook over medium heat for 10 minutes, stirring occasionally. Cool 2 hours or until room temperature, or refrigerate until serving time.
Serve caponata on slices of baguette-style French bread.