1. Preheat oven to 375°F (190°C).
2. In a large bowl, mix oil and vinegar. Toss with cubed vegetables.
3. Spread vegetables onto a metal baking sheet with low sides. (You’ll probably have excess oil, but make sure to not let that get in the pan or it might steam your veggies.)
4. Add salt liberally and sprinkle with pepper. Bake for 20 minutes, then raise the temperature to 450°F (230°C), and bake for another 10 minutes.