To my shame, I’ve never fully loved oysters. It’s the foodie equivalent of a hardcore fashionista saying ‘whatever’ to Alexander McQueen. Over the years, I’ve gone from ‘bleurgh’ through take ’em or leave ’em to an uneasy truce with the slippery bivalves. Until now.

We’re travelling round Etang de Thau in the Hérault region of the Languedoc, a vast inland lagoon. Its curious makeup – salt water stirred by fresh water from chalk hills – makes this area France’s leading producer of the finest Crassostrea gigas and Ostrea edulis. Our base is the hotel apartment complex and spa, Port Rive Gauche in Marseillan; our exquisitely decorated suite draws gasps of furious envy when I post a snap of it on Twitter. From our sunny terrace, we can make out the beginning of miles and miles of the peculiar oyster tables.

It’s at Le Glacier, an endearingly under-designed joint (hello, anaglypta), that I meet my life-changing bivalve. Called a Spéciale Tarbouriech, or Pink Diamond, it’s entirely unique to the eponymous producer, spending half its time basking in the sun and half submerged in the water. The large, lacy shell is edged with blush pink and its flavour is a revelation: sweet, oceanic, outrageously fresh, leaving in its wake a memory of the sea with subtle notes of hazelnut. We also learn to eat the connective tissue between shell and mollusc, la membrane, an extra little treat like a mini scallop. Who knew?

Horribly hungover – look, the crisp, fragrant local picpoul de pinet is too seductive – we’re not entirely up for a visit to Marseillan’s most famous native, venerable vermouth company Noilly Prat. Maybe it’s something to do with the fragrant aromas – unusually, barrels of wine are left in the open to absorb the salty air by osmosis – or maybe it’s the salty air itself, but we soon feel quite perky. Is it wrong to be necking cocktails, expertly mixed by Jean-Louis Mastoro, the twinkly Maître de Chai (cellarmaster), in the building’s VIP bar at ten in the morning? The deceptively innocuous little number is made with Noilly Prat Ambre, a sexy, honey-hued speciality only available here and nowhere else in the world. Guess what we’re taking home?

You could spend all your time pottering along the town’s little creek, where restaurants, cafés and bars populated by outrageously chic, platinum-helmeted and scarlet-lipped mesdames line the quayside. Our favourite is La Taverne du Port, which functions as local hangout, wine shop, oyster bar and truffle purveyor. A son of the owning family, Bruno Henri, is its linchpin, waxing lyrical about his extensive stock: everything from local biodynamic wines and recherché whiffy cheeses to uncommon malt whiskies.

Bouzigues, just down the road, is the heart of the ostreiculture industry. We drive past vineyard after vineyard, all specialising in picpoul; the wine and shellfish industries work together to ensure a splendidly symbiotic pairing. The place is awash with oystermongers producing and selling the shellfish – from shack to sophisticated restaurant; we choose Les Jardins de la Mer (Avenue Louis Tudesq, 34140 Bouzigues; 00 33 4 67 78 33 23) because of its vine branch-burning open oven and astonishing view over oyster flats stained almost burgundy by the deepening sunset. Teeny, whiskery brown shrimp, vast platters of fruits de mer, whole fish pleasingly scorched on the embers: simple stuff, simply served. Perfect.

Sète, on the other side of the lagoon, is often called the Venice of the Languedoc, its broad avenues interlaced with canals. Our lunch here isn’t a happy affair: overcooked fish bizarrely accessorised by soggy quinoa and dishes randomly set on fire for some kind of theatrical effect. We were hoping for the native bourride (fish stew), but that’s clearly so last century. The oysters? Blameless, but it would be outrageous if they weren’t. I’m not going to name and shame; oh, ok then: Au Bord du Canal. Seems that the days when you could be assured of a good meal anywhere in France are no more.

Our final night sees us back in Marseillan, in Delicatessen (4 Place Général Guillaut; 00 33 4 67 77 38 93) a funky, flea-market-furnished joint. There’s a handsome dog holding court at one of the tables while his equally handsome owner serves dinner. The blackboard menu is short and lovely: oysters (but you guessed that, didn’t you?), leek velouté, bone marrow dressed simply with fat flakes of sel de Guérande, eel from the lagoon, beef cheek and tail in meaty red wine, a towering burger topped with stinky cheese. Wine is decanted into old Ricard water bottles and sloshed into beakers; the suspiciously cheap ‘bill’ is scrawled on your table. Forget the peach drapery, improbable tableware and shiny trousers of the town’s ‘posh’ places – yes, La Table d’Emilie, I do mean you – this is the provincial France of all our fantasies.

The article 'Postcard from Etang de Thau, France' was published in partnership with BBC Olive magazine.