Heat oven to 400° F. Heat 1 tablespoon of the oil in a large nonstick sauté pan over medium heat. Add onion and celery; cook 5 minutes. Add garlic; cook 1 minute. Pour in another 1 tablespoon of the oil and add eggplant; mix well and cook 5 minutes. Add tomatoes, tomato sauce, vinegar, raisins, pine nuts and capers. Cook 5 minutes, then reduce heat to medium-low and cook 10 more minutes. Stir in 1/4 teaspoon of the salt and 1/8 teaspoon of the pepper.