Three wheels of butter like lumpy hassocks sat on a counter at Jean-Yves Bordier, the tiny, immaculate fromagerie hidden down a dark backstreet inside the walled city of St.-Malo. Although Bordier is an esteemed curator of cheeses, and France's best were shimmering on display by the dozens, the cashmere-draped ladies in line ahead of us had eyes only for the butter.
Two of the wheels were jasmine yellow, one marked DOUX, or "sweet," the other DEMI-SEL, or "salted." The third had no label and was flecked with green and lavender specks we took to be dried herbs. The man behind the counter, wielding a wooden paddle in each hand, pried a hefty chunk from the mammoth wheel of demi-sel, dropped it onto a sheet of waxed paper, and massaged it with his paddles into a small, tidy block, which he folded up in the paper and proffered to one of the women, who tucked it into her Goyard handbag and left.
And then it was our turn. We'd just driven four hours from Charles de Gaulle and were looking for a little something to spread on a baguette to tide us over until dinner. We summoned up our finest college French and a cool Jean Reno insouciance: "A quarter-kilo of the herb butter, please."
The man's face fell slightly. "It's not herb butter," he said. "I'm sorry. It's seaweed butter."
We nearly yelped with glee. Seaweed butter?We'd never before encountered beurre aux algues, but it seemed at once deeply old-world and strangely cutting-edge—exactly the sort of comestible we'd hoped to find when we set out for the windswept northwestern coast of France.
We'd been introduced to Brittany by a friend, Tom Moore, who'd spent his childhood summers in a farmhouse there and raved about its ocean-centric cuisine: a rustic, classic French, he had said, but with mystical influences thrown in—the enduring culinary legacy of the region's Celtic soul. During the Anglo-Saxon invasion of England, in the fifth and sixth centuries, some Britons sought asylum across the water, bringing their language, their rollicking music (heavy on harp and woodwinds), their traditional garb (including the bigoudène, a distinctive tall headdress for women) to a land they called Breizh. France annexed the territory in the 16th century, but the Breton culture, language, and separatist instinct have endured.
There are precious few volumes on the dishes of Brittany, but we eventually found its bible: Aimer la Cuisine de Bretagne ("Loving the Cooking of Brittany"), by chef Jacques Thorel. The book included recipes for dishes with exotic-sounding names that only deepened our interest in the place. Kig ha farz, we learned, was the signature Breton dish, a meaty, dumpling-laced soup; kouign amman was a rich, sugary butter cake. The photographs showed food that looked both medieval (a furry, lifeless rabbit posed with a hunk of raw pork) and contemporary (a scattering of clams, each with its own airy cape of foam, that seemed to have emerged from a new-wave Barcelona kitchen). We were curious what form such a cuisine would take in the new millennium.
So we charted a rough loop around Brittany, a broad peninsula that juts out toward England into the Atlantic. We would spend a couple of days in the northern fishing ports of St.-Malo and Cancale, then head southwest to Quimper, in the heart of cider-making country. We'd follow the region's southern coast east to the marshes of Guérande, source of the fabled fleur de sel, and circle back to Paris via Rennes, the Breton capital.
The seaweed butter was an early, favorable omen; spread on a fresh baguette, it had the sweet, creamy, salty flavor of a dense shellfish bisque. We had retreated from the tourist-choked streets of the walled city to the Chaussée du Sillon, a two-mile-long promenade overlooking the Gulf of St.-Malo, where locals were walking, bicycling, sunbathing, and kite boarding. We polished off our tartines on a narrow promontory that stretched so far into the shore break from the seawall that we felt we could reach out and touch the kite boarders launching themselves off the waves and into the air.