Acorn Vegetarian Kitchen, restaurant review: This little cracker is doing everything right

This bite-sized bistro is a newish venture with a venerable past

This is a first. Normally I do a bit of research about the restaurants I review, particularly when going to an unfamiliar town. But this week my research has consisted of a casual enquiry – "Where's good to eat around here?" – at the end of a morning meeting in Bath. Next thing, I'm being whisked down cobbled streets, through a blur of honeyed stone, to a mystery destination. Ten minutes later, I'm sitting in... this place. Wherever we are.

It's tiny – a set of pale, sunny, wood-panelled rooms, high of ceiling and quirky of framed ephemera. It's friendly – the young team greet us like long-lost friends. It's borderline trendy – they're playing "Skinny Love", and the staff are wearing skinny jeans. And it's – oh, right, it's vegetarian. OK, that's fine, that's great actually. I wasn't really hungry anyway.

This bite-sized bistro is a newish venture with a venerable past. In the not-overly-distinguished history of vegetarian dining in the UK, this site is a place of pilgrimage. For 26 years, it was Demuth's, run by food writer, cookery teacher and veggie pioneer Rachel Demuth. When she stepped aside last summer, she was bought out by two of her staff, chef Richard and manager Rob, who have renamed the place Acorn Vegetarian Kitchen and given it a discreet facelift.

The energy of the new team is palpable. There are signs advertising three-course Sunday roasts (nut, obvs) and vegan tasting menus and fab-sounding house cocktails. The menu abounds with sub-categories; little plates, dips, nibbles, starters, mains. If it were any busier, it would need its own executive PA. And the food is complicated, in that inventive, freewheeling style that inspired chefs reach for when they can't build around a big hunk of flesh.

Chef Richard Buckley's great strength is texture, but he's pretty damned good with taste, too. This is subtle, interesting stuff. We puzzled about the fugitive flavour informing the satin-smooth, tahini-ish panna cotta, wobbling alongside char-grilled broccoli (it was cauliflower) and just what vegetable had been pickled into those sharp, citric little cubes (kohlrabi, it turns out). Then we stopped puzzling, and just concentrated on eating it all.

Superb sourdough came with a nubbly, intense dukkah and pungent olive oil. Polenta chips, threaded with rosemary, offered a mouthful of airy crunch, or something more complicated when dipped into a plum ketchup.

A main course offered a wonderful riff on Indian street food; a sybaritic chickpea masala, all bite and spice, with a couple of miraculously light bhaji-like fritters and florets of griddled cauliflower, all dressed with a filigree of deep-fried kale. Even the humble hazelnut becomes a star ingredient, toasted to a crunch and scattered over a mound of pappardelle-like ribbons of celeriac, which have been marinated in sherry and cooked in hazelnut butter, then anointed with the subtlest porcini purée.

There were a couple of fails. The gluten-free bread requested by my intolerant guest was as dense and dry as a canary's seed-cake, and a salad of leaves dressed in some kind of sweet emulsion and served with candied pecans and wine-poached figs was a bit one-note. And please, no more with the slates and wooden boards instead of plates. Seeing a sage pesto soaking down into those pitted surfaces is no more reassuring than when it's blood from a rare steak.

That cliché aside, there's nothing to dislike about Acorn. The staff are great, helpful and funny. They're working with and promoting local producers. It's very reasonably priced; lunch, in particular is good value. And forget my silly comment about not being that hungry; this is a place for feast days as well as fast days. We certainly abandoned the central tenet of Michael Pollen's wise mantra – Eat Food. Not Too Much. Mostly Plants – when we applied ourselves to pudding, having chowed our way through a good part of the menu.

The short dessert list looks a bit ho-hum, but again, the results are more complicated than they sound, including an intense little chocolate pot, the ganache warmed with a hint of coffee and galvanised by candied pistachios and burnt orange marmalade jelly. With a couple of glasses of rosé each, and a slab of bloomy blue cheese, a well-kept Blue Vinny from Dorset, our bill came to around £30 a head. I had to double-take; it seemed a steal for food of this quality.

Weirdly, for a city that used to be one of the UK's foodie stations of the cross, Bath seems to lack much in the way of destination dining. I struggled to find recommendations for new and exciting openings there – hence the lastminute.com approach. But how serendipitous that turned out to be. It may be the first recorded case of a mighty oak turning into an acorn, but this little cracker of a restaurant is doing everything right.

Food ****
Ambience ***
Service ****

2 North Parade Passage, Bath (01225 446059)

Lunch £13.95 (2 courses)/£16.95 (3 courses)

Dinner £23.40 (2 courses)/£28.40 (3 courses)