Roasted Eggplant And Pepper Relish

Name: Roasted Eggplant And Pepper Relish
Ingredients: 4 x red bell peppers, seeded, cored and sliced thinly; 1 medium eggplant, cut into 1/4 batons; 1 large onion, halved lengthwise and then sliced very thinly; 1/2 cup plus 2 tablespoons good olive oil, divided; 1/4 cup good quality balsamic vinegar; 1 tbsp capers, drained and chopped; 2 x cloves garlic, minced; 2 tsp minced fresh basil; sprinkle of dried red pepper flakes (optional); salt and freshly ground black pepper