- Heat your oven to 230℃ /fan 210℃. Line a large baking tray with greaseproof paper.
- Place the peppers, courgettes and aubergines in a large bowl. Add the extra-virgin olive oil, balsamic vinegar and dried Italian herbs. Season with sea salt and freshly-ground black pepper and toss to combine.
- Arrange the vegetables in a single layer on the baking tray. Roast, tossing once halfway through, until cooked and slightly browned, 15 to 20 minutes.
- While the vegetables are in the oven, cook the orzo in generously salted water according to package instructions. You want the orzo to be cooked through, not al dente, as pasta hardens up when cold. While the orzo is cooking, make the sundried tomato pesto, if using homemade pesto. If not, you can use shop-bought pesto.
- Drain the orzo, rinse under cold water, and drain again. This helps remove some of the starch, which will make the pasta less gummy as it cools.
- Transfer the drained orzo to a bowl, add the roasted vegetables, baby spinach, basil and pesto to the orzo and stir to combine. Taste and season with salt and pepper, to taste, then serve.