Cod you can trust - Telegraph Yet skrei comes from one of the few sustainable sources of cod, as Kvalheim explained in the Antonsens" cosy candlelit living room. Every year from January to April the adult fish make the 500-mile journey from the Barents Sea, where they grow up, around the top of Norway to spawn just off the islands of Lofoten, a few miles south of Langøya. The abundance of mature fish close to shore has attracted fishermen here since the days of the Viking. The success of the fishery is partly due to the "no discard" policy adopted by Norway 25 years ago (a partial ban on discards in the EU is only now being proposed in the new Common Fisheries Policy). There is a ban on trawling too. Kvalheim estimates that more than 80 per cent of the skrei is caught on long lines from one-man fishing boats of less than 11m, the rest on larger boats using long lines and drop nets. The Norwegians also have a minimum size for cod of 44cm long (the EU standard is 37cm), meaning that boats entering Norwegian waters have to change to nets with a wider mesh. There is rigorous enforcement of no-fish zones too. The result is that after a shaky few years in the Seventies and Eighties, according to the Norwegian Seafood Council, cod stocks in the Barents Sea are now back to the same abundant levels as when monitoring first began, shortly after the end of the Second World War. Since 1995, skrei has had its own quality mark, which guarantees that the fish are cleaned and put on ice within 12 hours of leaving the sea. Rigmor, high-cheekboned, dark-haired and as statuesque as a Nordic goddess, served us fiskemølje, the traditional dish of skrei poached with bay leaf, pepper and, she says, "a handful of salt for each litre of water." The fish was exquisite, as mild flavoured as ordinary cod but with a firm, almost scallop-like texture with muscular flakes. The other key components of the mølje are oval slices of grainy, pale orange roe, and cod liver. The liver looked deeply unpromising, scraps of beige floating in oil like some rather ropey cat food. But that vitamin-D-rich oil, arriving as it did at the end of winter, was once vital for the local population after two months without sunlight. Rigmor explained how she cooked it, rinsing the pale pink liver and pulling out the membranes and tubes, then shredding the flesh with her fingers. A ladleful of the salty cooking water from the fish went into a pan, and with it the liver and a chopped onion, and it was poached for an hour until the oil ran. This in itself is enough to strike fear into anyone who suffered spoonfuls of cod liver oil as a child. I raised my fork with trepidation - and was converted. It was meltingly soft, mild, creamy and buttery, like the best foie gras but without the ethical ball-and-chain. And, sadly, too perishable to export. As for vegetables, not a bit of green sullied the plate. Traditionally, this far north vitamin C would have come from wild berries, such as the yellow, blackberry-shaped cloudberry. We did have potatoes, the small Mandel or "almond" variety, but as Arne pointed out, they are newcomers to the mølje. Spuds only became widespread in northern Norway in the 19th century. "You feel sleepy after a mølje," remarked Kvalheim, leaning back in his chair. "Nothing to do with the potato aquavit then," joked his deputy, Espen, raising the shot glass of pale yellow spirit. Skøl! We obediently drained our glasses. Next day, after a breakfast of toothpaste tubes of fish eggs and a rich, tomatoey mackerel pâté on dense, nutty rye bread, we headed out on the coastguard boat, powering past settlements of red, cream and slate-grey wooden houses tucked under the mountains that rise steeply above, jagged like the edge of a latch key. Along the banks of the fjord were 20ft-high wooden A-frame racks, on which the pairs of cod, tied together by the tail and slung over the pole, were drying just as they have done for hundreds of years. This dried fish, or "stockfish," sustained the Vikings on their long sea voyages and was traded throughout Europe by the Hanseatic League in the Middle Ages. It still fetches a high price in Italy, so much that recently lorry loads have been hijacked en route. At the tiny settlement of Stø, on the northern tip of Langøya, Kyrre Brun was baiting a long fishing line, hooks every couple of feet, with fat slices of frozen mackerel. Like most of the fishermen, he works alone on his boat, leaving every day at 6am and returning at 3pm . His father and grandfather were fishermen before him, and he has been fishing since he was 16 - for 39 years. As for his son, "he's an officer on a cargo boat. But I hope he'll be a fisherman. It's a perfect life. Made of stern stuff, these Norwegians, I reflected as I shivered. Like those long-distance-swimming skrei. Skrei is available from the fish counter at Harrods Food Hall (www.harrods.com), Booths supermarkets (www.booths.co.uk) and Whole Foods Market (www.whole foodsmarket.com)