Mary Portas at Leon I get a bit scratchy when I'm hungry. If I'm working with a new film crew I'll generally wheedle out the most reliable of the production runners and ensure they've always got a bag of healthy snacks for when my energy starts to dip. I'm currently finishing off a series for Channel 4 in which I attempt to kick-start the fortunes of British textile manufacturing by getting a team back on to the knicker machines in a Manchester factory. Needless to say, it's not all plain sailing. All the travelling and filming means meals are generally on the hoof and out of a supermarket carrier bag. As anyone who has ever worked with me will tell you, I really can't stand lunch to be a sandwich. My boardroom lunch from hell is one of those with a clingfilmed platter of sarnies at the centre of the table. Britain has seen a sandwich revolution in recent years - our fast-food chains are pretty good. Everyone knows I'm a fan of Pret A Manger (their coffee is the best in London). But of all the lunch chains, one seems intent on doing things differently. Leon, founded in 2004 (with recipes created by one of its three founders, Allegra McEvedy), now has 11 restaurants across central London. When I'm filming in the capital, some of the crew members will plan ahead so that there's a Leon within arm's reach. Leon is based on a simple idea - that food should taste good as well as do you good. Shopability The Old Compton Street branch (Leon's newest and biggest) has what I can only describe as a happy vibe. There's a large servery surrounded by seats and red leather booths, the best seats offering good views of Old Compton Street (where there's plenty to look at). For those who want to be part of the action, there are also a few chairs and tables out on the street. It was a cold day and a clever hoarding outside said that 'soup is back. Inside, the wholesome vibe is helped along by fun lampshades covered in retro French fruit bags and olive oil packaging; on the walls are vintage photos of the founders" family members on holiday. I spot one of the co-founders, Henry Dimbleby (son of David), picking tomatoes in Spain in 1976, all reminiscent of a time when life and food could be enjoyed at a more leisurely pace. Downstairs, there's a library full of old donated cookery books and a stand of Leon books, reinforcing the message that this is a company that cares about food. You order your food at the counter and a member of the team delivers it to your table. I plumped for the Moroccan beef and lamb meatballs served in a flavoursome plum tomato sauce (as endorsed by Gordon Ramsay), with some healthy brown rice. My friend went for a grilled breast of chicken marinated in lemon and garlic. Although it was a bit cold for salads on the day of our visit, I loved the magic mackerel and the original superfood salads - both freshly made and delicious. Leon isn't the cheapest place for a fast-food lunch - all the mains are a fiver or more and if you add in one of their raspberry lemonades and a side of coleslaw, you'll have little change left from a tenner, which is a bit steep for most people's lunch fix. Online You can delve deeper into the Leon view of life on its excellent website. I learnt that all of the ingredients are sustainably sourced from farmers Leon trusts - most foods are naturally low GI, and there are plenty of clearly labelled wheat-, dairy- and gluten-free options. There are also loads of fun videos on 'Leon TV" and even music recommendations. Verdict A little paragraph on the menu from the owners, Henry and John (Vincent), sums up their philosophy: 'We set up Leon because as children we got very excited about eating fast food - then as we grew up we realised that it made you fall asleep and wake up fat. I'm not a health freak by any means and love my food as much as the next person, but I find myself embracing what Leon is trying to do. So much of the fast food on our high streets may give you an instant kick but it also leaves you feeling sluggish and bloated. Leon may be pricey but this is genuinely delicious, nutritious food on the go. For now, it's only lucky Londoners who can enjoy it, but my guess is that Leon's vision is so good that it won't be long before it spreads its net wider. Well done, Leon. I'm proud Brits can deliver a brilliant retail concept such as this. Leon 36-38 Old Compton Street, London W1 Visited Thursday, 1pm Number of stores 11 What they sell Quality fast food Website leonrestaurants.co.uk Henry Dimbleby and John Vincent, co-founders