Preheat the oven to 220C/200C Fan/Gas 7. Line two large baking trays with baking paper.
Put the vegetables into a bowl, add the oil and season with salt and pepper. Toss until coated. Arrange in a single layer on the baking trays.
Roast in the oven for 30–40 minutes, or until golden and little crisp – turn halfway through if needed. Leave to cool on the baking trays.
For the dressing, measure all of the dressing ingredients into a jug. Mix well and season with salt and pepper.
Put the vegetables on a serving platter or in a bowl. Pour over the dressing and check the seasoning. Scatter with the feta (if using), mint and basil and serve.