Which world wonder are we seeking out this week?
We're making a pilgrimage to Galicia.
Ah, the famous camino — following the pilgrims' way across northern Spain to the tomb of St James in Santiago de Compostela?
No, it's more of an earthly quest – to find a little bit of heaven on a plate. We are on a gastronomic search for the king of Spanish seafoods.
Would that be lobsters, crayfish — or my favourite, oysters?
No, the tastiest seafood of them all — percebes .
What are they?
Percebes are tube-shaped crustaceans that cling to the granite rocks of the storm-bashed Galician coastline. They're scientifically classed as Pollicipes cornucopia , more commonly known as goose barnacles.
Barnacles? They must taste like rubber bands!
Far from it — they're delicious, with the flavour of sweet lobster and the texture of an oyster washed over with a tang of sea spray. Ask gourmet Spaniards about this star of the cocina and they will dissolve into lip-licking rapture.
So why haven't we heard of them?
Well, they're certainly not the best looking thing in the pantry. They resemble cartoon creatures from another planet, or some strange dish that you might see served in the Star Trek canteen.
Tell me more, Captain.
Fully grown, they have a sooty finger-thick trunk with a rose-coloured inner tube. At one end is a scaly head that attaches itself to a rock and at the other a diamond-shaped foot that looks like a dinosaur claw. At high tide this foot opens to reveal tiny pink tendrils through which the barnacle filters the surrounding seawater to feed.
Bizarre. So how on earth do you eat these ugly brutes?
Definitely not with a knife and fork. The correct method is to pinch the foot between your thumb and finger and pull the tasty inner tube out of its scaly case, twist off the claw and slip down the flesh in one.
Charming. Then what?
Just keep tucking in while they are warm. Percebes make fabulous finger food, and like all good Spanish feasts you should end up with more bits on your table at the end of the meal than at the start.
OK, I'll give it a try — order me a small plateful!
I'm afraid it is not as easy that. These barnacles are truly wild and only grow in a few remote places, so harvesting can be a hazardous business.
They thrive in areas that are exposed to the hard beat of the Atlantic waves, so the collectors, called percebeiros, have to clamber down steep rocks or try to jump from boats bobbing in the rough sea to reach them. Once on the rocks the harvester can easily get clobbered by a breaker or simply slip into the sea. Then there is the problem of what the fishermen call "percebes greed".
Is it like gold fever?
Yes, but much more dangerous, as collectors take fatal risks in pursuit of the bounty.
But why do they do it?
Money, of course — the barnacles can command whopping prices of up to 60 euros per kilo (£40) at the fish market. The fishermen's big season is Christmas, when percebes are the stars of the Spanish festive table. Unfortunately this also coincides with the some of the worst weather, so accidents do happen.
So where does all this take place?
The very best goose barnacles are found on the Costa da Morte — the Coast of Death — in north-west Galicia.
It doesn't have quite the same ring as the Costa del Sol, does it?
It's a wild, atmospheric landscape on the very edge of Europe that runs from Malpica , in the north, to Fisterra , in the far west. Its deadly name derives from the many lives lost from ships wrecked at sea or smashed on to its treacherous rocks. Only recently the Costa da Morte was in the news when the oil tanker Prestige split in half and disgorged its black cargo along the craggy coastline.
What happened to the seafood?
Harvesting shellfish was banned for months and there were grave worries about the percebeiros' livelihoods. After a lot of testing, the Spanish government has declared the beaches clean and the seafood safe, and percebes are once again being collected from the sea.
Hurrah, so where should I go for my first try?You should travel to the small fishing village of Corme during the first low tide of July, when percebes are plentiful and the weather is good – ideally, during the Fiesta de Percebes, when everyone tucks into mountains of the precious seafood enjoyed with plenty of local white wine.
And if I miss that fiesta?
Head down the coast to the gastronomic wonderland of the Galician sea lochs or rias. There are lots of tempting eateries on the way south, but try to hold on until you get to the seafood capital of O Grove , near Pontevedra . Choose a restaurant, check that it's serving the barnacles, and then sit yourself down for a steaming treat.
So how do they cook them?
Traditionally, they are very lightly boiled with just a touch of salt and a bay leaf, then served piping hot on a plate covered by a heavy napkin.
Something I can try at my holiday home?
Of course, but don't even think about gathering your goose barnacles from the local rocks. Besides the danger from the sea, each percebe patch is jealously guarded by locals and controlled by strict regulations and licences. Much better to buy them raw from the magnificent fish market in Plaza de Albastos , Santiago de Compostela.
And can I take them home with me?
They should remain fresh for about four days, although of course like most seafood they are best eaten on the day they are pulled from the sea.
Any other tips?
Yes, in proportion to its size, the barnacle has a larger sex organ than any other living creature. It's probably best not to dwell on this mind-boggling statistic when you are eating them for the first time. Much better to pour yourself a large glass of the local wonder wine, Albariño , sit back, close your eyes and think of Galicia.
Barnacles are not the only delicacy on offer in food-loving Galicia. With a little planning, it is possible to eat your way through the calendar on a gastro-tour of saints' days, each celebrating a particular homegrown speciality. Highlights of the year include: Pigs' ears festival at Sales-Vedra , in March; oysters at Arcade-Soutomaior in April; trout and kid at Pontecaldelas in May; peppers from Padrón (a national favourite) in August; cockles from Cabana y Ponteceso in September; and the big seafood festival in October at O Grove.