Meet "Mr Yin" and "Mr Yang", the pair on a mission to create a new chain of organic and ­artisan food stores. The duo have been working 20-hour days since the first outlet of The Natural Kitchen opened just over a month ago on thriving Marylebone High Street in London.

Mr Yin, aka Keith Bird (the tall, blond, clean-shaven one), came up with the idea two years ago when working as Asda's head of strategic planning (he devised the standalone non-food format Asda Living).

Realising he needed a Mr Yang to execute his masterplan, he enlisted the help of Asda store development manager Martin O'Connor, whose forte was opening new stores at the lowest possible cost.

"People describe us a Mr Yin and Mr Yang because we are so different, but this is what creates such a good working partnership," says Bird.

It has certainly created a great-looking store and one that at 5,700 sq ft arranged over three storeys is as far removed from the pair's big-box, low-cost roots at Asda as you can get.

A coffee and juice bar sits just inside the front door of the store, alongside the fresh-to-go deli and sandwich bar to catch the bustling passing trade. To the right is the organic meat counter manned by top-class butcher Deon, who greets customers with market-street banter.

There's also a treasure chest of a cheese counter, a licensed café, an organic wine vault and fruit and veg sourced from the Royal Farms at Windsor. "Meat is at the heart of our business, which is all about the renaissance of skills and the romance of the marketplace," says Bird. "We've seen how supermarkets go down the de-skilling route. Getting the real butchers and real cheesemongers was tough, but that's what people want, so let's bring it back."

One thousand applicants were whittled down to 53 shopfloor staff using a rigorous recruitment process. "It took a couple of years to get the concept together, and seven months to deliver the store," says O'Connor. "Three of these were spent getting the right people - the most important assets of this business."

If finding the right staff took time, finding the suppliers took even longer - 16 months - and include Hugh Fearnley-Whittingstall, Paxton & Whitfield and The Well Hung Meat Company. Getting brands to trust in the duo's start-up was tough, says Bird, but their belief and willingness to invest in the business (Bird sold his house) helped.

As did their business acumen, which attracted backers such as David Fitzjohn, former MD of Europe for KFC-owner Yum Brands, and The Times 100 rich list entrant Elliott Bernerd of property development company Chelsfield.

With all the pieces of the jigsaw in place, the attention turned to making the right impression with shoppers from day one.

O'Connor's 17 years' experience at Asda taught him that if you want a store opening to go smoothly, it helps if your staff are relaxed. One of his tricks included keeping the fish counter hidden behind a false wall and pre-packed fish unit. This allowed the butcher, who doubles as the fishmonger, to get to grips with the meat counter first.

The Natural Kitchen has already caused a stir, with Michael Winner telling Sunday Times food lovers it's a must-go and many celebrities have been spotted, including Noel Gallagher and Barbara Windsor. But even Bird and O'Connor have been shocked at the spending power in London - the highest basket spend hits the £1,500 mark - a far cry from Asda price.

Now the pair are looking to the future. Store two is set to open soon and though the duo are coy about their long-term ambitions, they do admit to creating a top 10 of ­London streets on their hit list for new stores.

"We would not have given up what we have for this to be just one store," says Bird.n