Preheat the oven to 180°C.
Cut the onion into wedges, the bell pepper into chunks, and the courgette into thick rings.
Arrange them in a baking tray, then tuck the garlic cloves (unpeeled) between them.
Scatter the oregano, salt and pepper on top, then add the olive oil and balsamic vinegar. Toss well, then roast in the oven for about 25 minutes, until soft and lightly charred.
Remove the tray from the oven, let the veggies cool, then discard their skins.
Put the rice and drained chickpeas in a mixing bowl.
Add the roasted vegetables, including the cooking juices, then toss gently.
Add the chopped herbs, season to taste, then mix.
Serve lukewarm.