Bill's Produce Store, 28 St Martin's Courtyard, London

Ah, what could be more comforting on a January day than eating in a cosy farm shop? The higgledy-piggledy piles of produce, the chalked-up daily specials, the benches nailed together out of old planks, the locally-sourced ingredients. All of these attractions are abundantly on offer in the latest branch of Bill's Produce Store. Apart from the last. Because – weirdly, for a business which is all about localness and authenticity – this rustic idyll is situated in a new-build development in London's Covent Garden, around the corner from The Ivy.

The Ivy reference is relevant. Bill's, which started as a store-front café in a Lewes grocery, shares ownership with London's starriest restaurant, after the Sussex-based business was acquired in 2008 by restaurant mogul Richard Caring, who also owns Caprice Holdings and the Soho House group.

In the quirky authenticity of the original Bill's, and its sister café in Brighton, Caring clearly saw the opportunity to isolate the DNA of the ideal farm shop café – laid-back, community-based and picturesquely ramshackle – and to clone it. A town-centre opening in Reading is followed by this London branch, which joins businesses like Laura Ashley and Daylesford Organic in offering thesis material to future social historians charting the marketing of rural authenticity to jaded urbanites.

Crossing the threshold into Bill's after a hellish session at the Oxford Street sales was like moving from grim social realism into the soft-focus embrace of a Meryl Streep romantic comedy. Outside, a concrete and glass arcade; inside, a glowing Aladdin's Cave of foodie treasures, with vertiginous shelves lined with bulging bags of rice, own-label preserves and artisan olive oils. Even the smiley young woman who greeted us came accessorised with her own fresh produce, juggling an armful of oranges as she directed us to our table .

It's undeniably picturesque, this rus-in-urbe idyll, apparently created in some old light-industrial building. Until you realise that the whitewashed brick walls, reclaimed furnishings and exposed ducting all appear to have been imported on to an empty site and painstakingly reconstructed from a designer's look book. All the homely touches – candles guttering in jam jars, cutlery stuffed into porridge tins, newspapers scattered around battered leather armchairs – are similarly ersatz. So pervasive is the illusion that I began to peer at the signage which covers every flat surface, to see if it was genuinely hand-written or printed off in that special font called "Arty Manageress".

With towers of spotlit produce dominating the room, Bill's comes over as a foodie paradise. And then you look at the menu. Tomato soup; avocado and bacon salad; salmon with hollandaise; hamburger; minute steak and chips. Special of the day: T-bone steak. The stuff of every bog-standard brasserie, in other words, with no particular focus on seasonality or provenance, unlike the original Bill's, which built its menus around produce from local farms.

Surrounded by esoteric food-stuffs, we worked our way through a pretty average meal. Fried calamari rings, under-seasoned and served with a garlic dip that put the "meh" into mayo. A mulch of chorizo and tomato on chargrilled bread which called to mind pasta sauce on toast. A prawn curry that was no more than curry sauce on rice, topped with a few chargrilled prawns; chicken paillard with spring onion mash, and a burger distinguished only by its glossy brioche bun. All perfectly OK, and not unreasonably priced, with starters around £5, and mains £8-£11.50, but nothing special.

The staff are lovely, and our twinkly waitress seemed intuitively child-friendly, offering to bring out our younger child's meal when it was ready, as she saw a tantrum unfolding. But the kitchen didn't comply, and all our dishes came to the table before the crying child's fishfinger sandwich, which followed after a gap of a few minutes that seemed to last hours.

Desserts come from the same usual-suspects recipe book – sundae, cheesecake, chocolate brownie, tiramisu. Vanilla panacotta and fresh fruit pavlova were both served with a coulis on an icing-sugar-dusted plate, a flourish at odds with the vintage crates and flour-bags around us.

With a couple of bottles of Bill's Beer, a golden ale brewed at Harvey's Brewery in Lewes ("two local family businesses working together," as the menu disingenuously puts it), Bill's bill came to around £25 a head. The displayed produce can also be bought to take home, so you can stock up on mandarin oil and Dulce de Leche while eating your fishcakes.

Despite an unfavourable location, Bill's was busy on a Bank Holiday Monday evening. Just why so many young people, in one of the most exciting cities in the world, would opt to eat in a fantasy farm shop is something of a mystery. Bill's – no doubt coming soon to a high street near you – is friendly, warm, bustling and golden. And I couldn't wait to get the hell out of there.

Bill's Produce Store, 28 St Martin's Courtyard London WC2 (020-7240 8183)

Food
Ambience
Service

Around £25 a head including drinks and service for three courses

Tipping policy: "Service charge is 12.5 per cent discretionary, of which 100 per cent goes to the staff; all tips go to the staff"

Side Orders: Down on the farm

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