Cut the potatoes in half lengthwise, and slice each halve into 4 equal wedges.
For the carrots, cut in half crosswise into two chunks. Slice each chunk lengthwise into 2 pieces, and cut each piece into 2 or 3 wedges, making them roughly the same size as the potatoes.
Put the potato and carrot wedges into a bowl and toss with the oil, cumin, pepper and salt.
Arrange on baking sheet lined with parchment paper.
Bake for 30 minutes or until the flesh is tender and the outside is lightly browned and the edges slightly crisp.