Heat the oven to 220C/200C Fan/Gas 7.
Cut the courgette and aubergine into 5mm/¼ in slices. Cut the peppers in 5mm/¼in strips.
Place all the vegetables in a roasting tin with the garlic and drizzle with oil. Season well with salt and pepper.
Roast the vegetables for 20 minutes.
Toss everything together and return to the oven for a further 5-10 minutes, or until hot.
Remove from the oven and leave to cool.
When cool, toss the vegetables with balsamic vinegar and serve.
