Preheat the oven to Gas Mark 4, 180ºC, fan 160ºC. Put the carrots in simmering water for 10-15 minutes until they are just tender but still slightly resistant to the tip of a knife. Drain well and tip into a roasting tin.
Add the olive oil, cumin and coriander, plus plenty of seasoning, and toss together. Roast for 45 minutes until tender and starting to brown at the edges.