In a Dutch oven, saute eggplant in 1/4 cup oil until tender. Remove from the pan and set aside. In the same pan, saute onions and celery in remaining oil until tender. Stir in tomatoes and eggplant. Bring to a boil. Reduce heat; simmer, uncovered, for 15 minutes.
Add the olives, vinegar, sugar, capers, salt and pepper. Return to a boil. Reduce heat; simmer, uncovered, for 20 minutes or until thickened. Serve warm or at room temperature with baguettes.