Cut evenly, toss with a teaspoon of oil, and shake once or twice.
Vegetable chart
| Vegetable | Cut | Temperature | Time |
|---|---|---|---|
| Asparagus | Whole spears, ends trimmed | 205°C / 400°F | 6–8 min |
| Broccoli | Florets, 3–4 cm | 190°C / 375°F | 8–10 min |
| Brussels sprouts | Halved | 190°C / 375°F | 15–18 min |
| Carrots | Sticks or 1 cm coins | 195°C / 380°F | 12–15 min |
| Cauliflower | Florets, about 3 cm | 190°C / 375°F | 12–15 min |
| Corn on the cob | Whole or halved | 205°C / 400°F | 10–12 min |
| Green beans | Whole, trimmed | 190°C / 375°F | 7–10 min |
| Mushrooms | Halved or quartered | 190°C / 375°F | 8–10 min |
| Bell peppers | Strips, 2 cm | 195°C / 380°F | 8–10 min |
| Potatoes | 2 cm cubes | 205°C / 400°F | 15–20 min |
| Sweet potatoes | 2 cm cubes | 205°C / 400°F | 15–18 min |
| Zucchini | 1 cm slices or half-moons | 205°C / 400°F | 10–12 min |
The basic method
- Cut to an even size so everything finishes together.
- Dry washed vegetables well. Water causes steaming.
- Toss with oil: about 1 teaspoon per 250 g is plenty. Add salt and seasoning.
- Preheat, then cook in a single layer, shaking once or twice.
- Taste a piece at the low end of the time. Vegetables are done when tender with browned edges.
Mixing vegetables
To roast a mix, group vegetables by time. Start dense ones like potatoes and carrots first, then add quicker ones such as peppers, zucchini or broccoli partway through. For example, start potato cubes at 205°C for 8 minutes, then add broccoli and peppers and cook 8–10 minutes more. Light, leafy pieces can blow around in the fan, so toss them with oil so they stay put.
Frozen vegetables
Cook frozen vegetables straight from the freezer at 205°C / 400°F. They take a few minutes longer than fresh, and they release water, so shake more often and don't overfill the basket. Toss with oil after the first 5 minutes, when the ice has melted, so the oil and seasoning stick.
Questions people ask
Why are my vegetables burnt on the edges but hard inside?
The pieces are too large for the temperature. Cut smaller, or lower the heat by 15°C and add a few minutes.
Do I need oil at all?
Vegetables cook without oil, but they'll look dry and won't brown much. A teaspoon makes a big difference.
Can I use foil?
Use a small piece only, with gaps around it, and never let it touch the heating element. Check your manual first.
Related guides
Reviewed October 2026. Temperatures from Health Canada and the USDA; see Sources.