Cut onion and tomatoes into eight wedges each; thinly slice eggplants and zucchini lengthways.

Cook onion, tomato, eggplant and zucchini with squash and capsicum, in batches, on heated oiled grill plate or BBQ until vegetables are browned lightly and just tender.

Meanwhile, place ingredients for balsamic dressing in screw-top jar; shake well.

Combine vegetables in large bowl or on serving platter. Drizzle with dressing; toss gently to combine.