It's also the kind of food that you would expect to have confiscated at customs; if I were an official, I should be dead suspicious at the sight of a whole tuna roe, pressed and salted. Not unlike a caveman's club, it is sealed with a papery skin flecked with crystalline salt that has the sheen of granite, a sturdy 12 inches in length, tapered at one end and blunt at the other. It is altogether different from grey mullet bottarga, which is as smooth and glossy as a wax candle, and burnt orange right through to the inside. Apart from being much smaller, it is completely different in flavour from the tuna, altogether more subtle with a concentrated taste of sea urchins, in contrast to the anchovy-tinge of tuna roe.
A Sicilian pronounces bottarga with the emphasis on the ar and a very soft o: bot-arrr-ga, a gentle growl, this was how my friend Natalia Ravida used to say it. Together we visited a bottarga factory on the southern coast of Sicily not far from her family's farm, and together we'd been rather spooked by the office, which was hung with pictures of the gory mattanza, the tuna kill, a ritual every bit as bloodthirsty as a bullfight.
It takes place in the spring, when the tuna run is at its fullest and they race off the coast, in a vast shoal. The fish are cordoned off with nets and led into a series of pens, followed by a fleet of boats with all the frivolity of the Henley regatta. What follows, though, is a bloodbath, as the tuna, which are now crowded and writhing, are harpooned by men standing on the side of the pens, and the water turns red. It was a fishing system invented by the Arabs in the 9th century, and if you can turn a blind eye to the gore of the occasion it is exquisite in its timing simplicity. There is an 18th-century engraving by A Bova in Mary Taylor Simeti's book Sicilian Food which shows how the most basic geometry has been superimposed on nature to man's advantage. In reality, such fishing is dying out as the tuna change their migratory patterns. The memory, though, is dear to Sicilian culture.
But enough of Sicilian bottarga. The importer Michele Cecere, whose company, Med Cibo, imports Sardinian bottarga, maintains that this is the finest. Not having compared it with Sicilian or any other, I cannot vouch for it, except to say that his is indeed excellent. In Sardinia, where mullet bottarga is preferred to the tuna, the finest fish are those found in the Stagno di Cabras, caught using a boat called Su Fassono, made out of reeds and bog grass that's carried by the fisherman on their backs down to the lagoon, and here it is put out to sea to catch the fish in nets.
The roes are salted, pressed and finally wind-dried, by which time they are so well preserved that in the days of the Phoenicians they were stored for up to three years. To them it was a precious food to carry on their lengthy sea voyages as they settled around the Mediterranean. They are supposed to have introduced it to Sardinia as long ago as 1200 BC when they conquered the island.
Once again my fridge is looking good, with its whole bottarga, though it is disappearing with the same speed as a stick of French bread and a pot of Gentleman's Relish. In fact, bottarga goes surprisingly well with thinly sliced French bread and butter, just as it does shaved over warm new potatoes or a creamy yellow mass of scrambled eggs. I haven't actually got any further with it, there's no need; it's one of those luxuries that shines far too brightly on its own to merit any dressing up.
Warm salad of new potatoes and bottarga, serves 4
You can use either tuna or mullet bottarga here. For the tuna, slice off the outer skin before shaving it; this isn't as necessary with the mullet although it does have a fine casing. I also find that, whereas the tuna roe can be shaved into very fine slices and is quite crumbly in texture, the mullet is nicer coarsely grated.
1kg small, waxy potatoes
150ml white wine
sea salt, black pepper
8 tbsp extra virgin olive oil
squeeze of lemon juice
112 tbsp finely chopped flat-leaf parsley
Bring a large pan of salted water to the boil. Peel the potatoes and cook until they are tender. Drain them into a sieve and leave them for 10 minutes. Slice the bottarga wafer-thin using a sharp knife.
Place the white wine in a small saucepan and reduce it to a syrup. Season it and add the olive oil and a squeeze of lemon juice. If the potatoes are small, leave them whole, otherwise slice and place them in a large bowl, toss them with the dressing, then add the parsley. Very gently fold the bottarga into the potatoes. Eat the salad straightaway, although it's still delicious a couple of hours later when it's cooled down.
Spaghetti with bottarga, serves 4
This is the most basic way I know of serving bottarga, the beauty of it aside from the sheer ease of preparation being that you can fully enjoy its deeply savoury nature with nothing to interrupt it. You can use either mullet or tuna bottarga, although I've tested the recipe using the tuna, which is the stronger of the two, so you might like to step up the amount if you're using mullet. It's also worth locating a really good artisanal spaghetti if you can.
12 tbsp extra virgin olive oil
2 heaped tsp red chilli, finely chopped
juice of 1 lemon
6 tbsp flat-leaf parsley, finely chopped
200g bottarga, skin removed and grated
Bring a large pan of salted water to the boil. Combine the oil, chilli, lemon juice, the parsley and black pepper in a large bowl, and gently mix in the bottarga. Add the spaghetti to the boiling water and cook, testing frequently towards the end to catch it while it is still firm to the bite, then drain it into a sieve, and leaving it quite wet, tip it into the bowl with the dressing. Toss it and add a little salt if you feel it needs it, and serve straightaway.
Bottarga is available from Med Cibo, 14c Crewson Road, London SW9 (0171-587 1188); 5th Floor, Harvey Nichols, Knightsbridge, London SW1; and Carluccio's, 28a Neal Street, London WC2.