Truffle

Brush off soil with a soft brush, then wipe it with a barely damp cloth. Rinse only if it is very dirty, and dry it straight away; soaking can dull its aroma.

Fresh truffles are often shaved raw over hot food, where the heat releases their aroma without cooking it away. If adding them to a sauce or risotto, stir them in right at the end.

Wrap each truffle in dry kitchen paper and keep it in a sealed container in the fridge. Change the paper daily and use the truffle within a few days, while its aroma is strongest.

Its earthy aroma works especially well with eggs, butter, pasta, potatoes and creamy dishes. Shave it over scrambled eggs, fresh tagliatelle or a finished risotto just before serving.

Yes. Freeze the truffle whole in an airtight container, then grate or shave it while still frozen; thawing can make it soft and watery. Freezing preserves it, but some of its aroma may fade.

Choose one that feels firm and has a strong, pleasant aroma. Avoid truffles that are mushy, shrivelled or smell sour; a little soil on the outside is normal.

There is no exact substitute for its distinctive aroma. A little truffle oil can add a similar flavour to a dish, but many truffle oils use flavouring rather than real truffle, so it will not taste quite the same.

A truffle is an underground fungus that grows in association with the roots of trees, rather than a plant or a typical mushroom growing above ground. Its aroma helps attract animals that dig it up and spread its spores.