Alice Zaslavsky’s cheesy root vegetable bake recipe: start with a cold oven and finish on a high

In her fortnightly food column, cook and author Alice Zaslavsky shares her technique for cooking through underground vegetables – and a recipe for a tian gratin

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One of the most useful rules for cooking vegetables is this: if it grows above the ground (stems, leaves!), start it from hot; if it’s grown mostly underground (roots, tubers!), start from cold.

This is especially useful to remember for boiling and simmering: broccoli should go in boiling water, spuds should be brought up to boil. But it also applies to roasted vegetables. Your underground friends could benefit from a slower start – like a parboil, or a cold oven.

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