Last year, if you came to New Norfolk's mental asylum, it was for artist Mike Parr's shock-inducing Dark Mofo performance. The irony isn't lost that a year later, festival-goers are taking the same 35-minute drive from Hobart for lunch. It's undeniably strange to be basking in winter sun, knowing the rattle of cocktails is replacing one-time calls of despair. But you could also imagine far worse candidates for ushering Willow Court into a brighter future than Rodney Dunn and Severine Demanet.

For the past decade, the duo have been salving souls at the Agrarian Kitchen Cooking School in Lachlan, 45 minutes' drive from Hobart. There in a crook of the Derwent Valley you pluck produce, pat goats, make preserves and eat lunch in the farmhouse of your dreams. Copper pans glow. Fires burn. Majestic geese waddle free among hens. It's possibly the most therapeutic place on the planet. And now, most of the perks, minus the gumboots, are here to heal the masses from Fridays to Mondays in what was once the Bronte wing.

Pressed tin ceilings and rows of tall windows are the only reminders of a ward. The room is now filled in equal parts with plump cakes, smooth ceramics and the gentle smell of smoke. For the most part you'll be here to build a lunch of charcuterie, hyper-local produce and probably an all-in roast trimmed by myriad sides. At night it's a share-style set menu that might include big tureens of beef bourguignon and raclette melted straight over the fire.

It's become problematic to describe Agrarian's food of almost zero food miles (some produce comes from the farm, other ingredients are sourced locally), that's often pickled, fermented and wood-fired to the hilt, and where everything is made in-house, from their three-day risen, chewy-crusted sourdough to fresh-churned butter, without grouping it with everywhere that's hammered those terms till they bleed.

Suffice to say, the Agrarian Kitchen is what those places hope to be when they grow up.

Fat ovoids of local kennebec potatoes become the ultimate potato cakes of naturally sweet, starchy glory. They hit the table with a sharp mustard-forward tomato kasoundi with the unfakeable depth and clarity only gained over time. Unsurprisingly you'll find it's often those condiments that make dishes pop. With fat-rippled ruffles of coppa di testa (pig's head terrine), crunched up with pangrattato and tarragon, it's salted cumquats given a lime pickle treatment bringing the dish into focus.

Head chef Ali Currey-Voumard comes via the McConnell group. You'll see some family resemblance. Scratch the surface of any of the seemingly simple dishes and you'll find a world of complexity beneath. A crescent of pumpkin, skin scorched, belly soft, sits in a smooth sauce of pumpkin seeds, green tomatoes and smoked chillies that reads somewhere between a peanut butter and tomato sandwich and a mole – with all the grunt work that entails.

Another wood-fired win of half a singed cabbage, mounted with seeds and pale wild mussels, is lubricated by a direct lift from Moon Under Water – a rich emulsion thinned by mussel liquor, and enriched by a dried powder of the bivalves.

Your most pressing and probably only problem dining here is the presence of Adi Ruiz (one of the bartenders who shook Sydney's Bulletin Place to glory) and your distance from Hobart. An Uber is as expensive as a Rondo and fresh grapefruit juice garibaldi is delicious. There again, scheduling three hours for lunch is advisable, which gives you time for one, plus a Hughes and Hughes skin contact sav blanc, or a juicy Architects of Wine field blend from a natural-leaning list that tries to reach no further than South Australia.

You'll be pressed to worry about much else. Order the main event of the day, you don't even need to make a decision. For us it's a wood-grilled joint of their own wessex saddleback-berkshire pigs, the meat dark, and sparkling with salt. With it dutch creams and purple congo potatoes lightly greased and horseradish-spiked; a flush of leaves in a fish sauce dressing, and a rich, foot-ripe gratin of mustard greens and swedes make sticky with local tilsit.

If that plus a wheel of blueberry-filled sponge or a wedge of custard tart with pastry so short if explodes on impact isn't enough to make you book a flight or ferry, truly, you are insane.