Heat the oven to 220°C (fan). Toss the carrots, red onion, and fennel with olive oil and salt. Spread onto a baking tray and roast for 20–25 minutes until tender and caramelised.
Spread some pesto onto a serving plate or bowl. Arrange the roasted vegetables on top and spoon over a little more pesto.
Scatter over the toasted pine nuts and micro herbs, if using.