1/4 cup extra-virgin olive oil
1 garlic clove, minced
2 large Japanese eggplants, trimmed, quartered lengthwise
2 zucchini, trimmed, quartered lengthwise
2 yellow squash, trimmed, quartered lengthwise
2 large whole tomatoes
1 ear of yellow corn, husked
1 small white onion, quartered through stem end with some core still attached to each piece
1/2 cup thinly sliced fresh basil