1. Preheat the oven to 425 degrees F. Cover a baking sheet with foil for easy cleanup.
2. Slice the carrots and parsnips diagonally into 1-inch slices (they are prettier this way).
3. Place the sliced carrots and parsnips on the baking sheet.
4. Toss the vegetables with olive oil, salt and pepper then place them in the oven for about 25-35 minutes.
5. Half way through cooking toss the vegetables around so they roast evenly. The carrots and parsnips should be slightly caramelized and tender.
6. Remove from the oven, toss with the chopped mint then serve.