1. To prepare sauce, combine first 6 ingredients in a small bowl, and stir with a whisk. Set aside.
2. Preheat oven to 475°.
3. To prepare eggplant, slice the eggplants in half lengthwise; score cut sides with a crosshatch pattern. Place the eggplant halves, cut sides down, on a baking sheet coated with cooking spray. Bake at 475° for 7 minutes or until slightly tender and browned. Remove from oven; carefully scoop out pulp, leaving a 3/4-inch shell. Reserve pulp for another use. Season cut sides with 1/4 teaspoon salt.
4. Combine remaining 1/2 teaspoon salt, onion, and next 11 ingredients (through chickpeas) in a food processor; process until smooth. Spoon 1/2 cup chickpea mixture into each eggplant shell. Bake at 475° for 25 minutes or until eggplant halves are tender and chickpea mixture is lightly browned.
5. To prepare relish, combine the tomato and remaining ingredients in a bowl; stir to combine.
6. Place 1 eggplant half on each of 4 plates. Top each half with 1/4 cup relish and 1 1/2 tablespoons sauce.