Preheat the oven to 200°C, fan 180°C, gas 6. Cook the carrots in a pan of boiling water for 3 mins, then drain well.
Tip into a roasting tin and sprinkle with the thyme and fennel seeds. Drizzle over the olive oil and season with black pepper.
Place the carrots in the oven for 35 mins or until tender and golden.