Heat oven to 220C/200C fan/gas 7. You can do this while the turkey is resting. Place the carrots on a large baking tray, toss with the oil and plenty of salt, then spread out in an even layer. Cover with foil and roast for 10 mins, then remove the foil and cook for 20 mins more.
Drizzle with the syrup and scatter over the nuts, then return to the oven for a final 10 mins until the carrots are soft and golden and the pecans toasted.