- Preheat oven to 500°F.
- Spray 2 large baking sheets with oil spray.
- Arrange eggplant rounds on prepared sheets; brush lightly with 1 tablespoon oil.
- Sprinkle with salt and pepper.
- Bake 10 minutes.
- Turn rounds over and bake until tender and golden, about 10 minutes longer.
- Remove from oven.
- Reduce oven temperature to 350°F.
- Heat remaining ½ tablespoon oil in medium nonstick skillet over medium heat.
- Add onion; sauté‚ until tender, about 5 minutes.
- Add garlic and stir 1 minute.
- Season with salt and pepper.
- Add tomatoes with their juices, mint and oregano and simmer until sauce thickens and is reduced to 1¾ cups, breaking up tomatoes with back of spoon, about 20 minutes.
- Spoon half of tomato sauce into shallow 2-quart baking dish.
- Arrange eggplant rounds atop sauce, overlapping slightly.
- Spoon remaining sauce over.
- Sprinkle cheese over.
- Bake until heated through, about 20 minutes.
- Sprinkle with basil.