How do I roast vegetables properly?

The difference between excellent and disappointing roast vegetables is almost entirely about moisture. Browning needs a dry surface and high heat. Crowd a tray and the moisture the vegetables release can't escape, so they steam instead — same ingredients, same time, completely different result.

What you'll need

• Large baking trays
• Oil with a reasonably high smoke point
• Salt
• Kitchen paper for drying (optional)

Step by step

1. Heat the oven to 200–220°C (fan 180–200°C) and put the trays in to heat.A hot tray starts the browning the moment the vegetables touch it.
2. Cut the vegetables into evenly sized pieces.Even sizes means even cooking. Group similar-density vegetables on the same tray.
3. Dry the vegetables well, especially if they've been washed.Surface water has to evaporate before browning can start, so it's directly costing you colour.
4. Toss with enough oil to coat lightly, plus salt.Roughly a tablespoon per large tray. Too little and they dry out; too much and they go greasy.
5. Spread in a single layer with space between the pieces.This is the critical step. If they're touching, use another tray.
6. Roast without disturbing for the first 15–20 minutes.Let a crust form before turning. Early stirring stops browning from establishing.
7. Turn once, then continue until browned at the edges and tender in the middle.Typically 25–45 minutes total depending on the vegetable and the size of the pieces.
8. Season again at the end, and add anything delicate — garlic, herbs, lemon — in the last 10 minutes.Garlic and herbs burn over a full roast. Add them late.

Tips

• Parboiling potatoes for 8 minutes and roughing up the surfaces in the colander before roasting is what produces genuinely crisp roast potatoes.
• Root vegetables want 200–220°C; softer vegetables like courgette and peppers do better around 200°C and cook faster.
• A little acid at the end — balsamic, lemon — lifts roasted vegetables considerably.
• Line trays with baking paper for easy washing up, but note you lose a little browning from the direct metal contact.

Common mistakes

• Crowding the tray — Trapped steam means the vegetables stew instead of roasting. It's the single most common cause of pale, soggy results.
• Oven not hot enough — Below about 190°C you dry vegetables out before they brown.
• Stirring too early or too often — Prevents a crust forming, which is where all the flavour is.
• Adding garlic at the start — It burns long before the vegetables are done and turns bitter.

Questions people ask