Everything you need to know about ... sea urchin

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The spiny armour of these simple sea creatures hides a rich and luscious interior. A delicacy in Europe and Asia, Australian chefs are making the most of native species using umami-rich urchins in pasta sauce and to top steak tartare.

What is it?

Ancient denizens of the sea, sea urchins are endemic to most of the globe's waters. They live on the sea floor and dine mostly on algae.

Inside these prickly, globe-shaped creatures is a simple alimentary canal and five large lobes of roe. The roe has a slippery yet creamy, buttery texture that has a fresh, salty seafood flavour with a clean finish.

Australia has many urchin species but one of particular interest is the long spine sea urchin, which has moved with warmer currents from its home off the NSW coast to Victoria and Tasmania.

There it devastates the kelp (brown algae) forests. These pests are targeted as a food species, alongside indigenous species, and hand-harvested by divers.

Why do we love it?

"Sea urchin is rich and buttery, a decadent and naughty food," says Pip Pratt, executive chef at The Rover in Surry Hills, Sydney. "Most rich food fills you up, but urchin is light. I love it because you can spread it, eat the roe whole as is or use it in a sauce as a fresh, sea-like flavour enhancer."

At The Rover, lobes of roe are draped over a mound of finely chopped steak tartare, the creaminess working with the minerality of the raw beef.

Melbourne chef Joseph Vargetto used to dive for urchins off the beach at Brighton, treating them like oysters and eating the flesh raw with lemon, washed down with a crisp white wine.

At his Kew restaurant Mister Bianco, he serves fine hand-cut fresh spaghettini with a creamy sauce of cultured butter, pureed sea urchin roe and vermouth, garnished with fresh urchin roe.

How do you use it?

If using live urchins, wear a sturdy glove.

1. Find the mouth opening at the base and use sturdy kitchen scissors to make two equal and opposite cuts halfway down the urchin.
2. It will now split apart easily.
3. Remove the five lobes of roe.
4. Wash in salted water and remove darker membrane. It is now ready to use.

Lay fresh lobes over nigiri rice to make the classic Japanese uni sushi. Serve it as a tasty side to Spanish cold almond soup. Add urchin roe and cold butter to a seafood risotto for extra creaminess and umami. Whisk raw urchin through eggs and a little cream to make silky smooth, just-set scrambled eggs topped with salmon caviar.

Where do you get it?

Buy live sea urchin from fish markets and fishmongers. Look for fresh processed roe from local processors. Keep live urchins in the fridge for two days if you are going to eat them raw, or five days if you are going to cook them.

Send your culinary conundrums and ingredient suggestions to brainfood@richardcornish.com.au or Twitter and Insta @foodcornish.