marinated eggplant with capers and mint

INGREDIENTS

• 1 pound thin Italian or Asian eggplants (2 to 3), cut into 1/4-inch-thick rounds
• 5 tablespoons extra-virgin olive oil, divided
• 2 tablespoons red-wine vinegar
• 1/4 cup chopped mint
• 2 tablespoons small capers, rinsed