Even My mother would like this,’ the most unlikely words to have ever been uttered in a fast food restaurant.

But then this is no ordinary fast food restaurant. It’s Leon, and my children were happily munching through halloumi wraps and ‘super grilled chicken pot’ sides, while discussing the merits of the orange juice versus the lemon, lime and ginger refresher, and dipping flat bread into pots of hummus.

It was as far away from the burger/ chicken/chips/milkshake fast food mentality as it is possible to be.

Not that we’d known what to expect, curious about Leon since it opened on Cornmarket, opposite Burger King like two cowboys in a shoot-out.

With Wasabu Sushi and Bento over the road and Itsu a few shops down, the tide has turned it would seem, the intoxicating and repellent waft of fat and sugar which hits you on Cornmarket Street suddenly seeming as old fashioned as a donkey ride – a modern day stake out between the gaudy excesses of the fat-laden wonder years and the 21st century’s answer to the unhealthy fast food conundrum.

Which is actually how it was conceived of course, two guys wanting to eat quickly without having to worry about having a heart attack, who came up with Leon.

What is even more miraculous is that when we appeared at 11am, brunch was still on the menu- porridge, bircher muesli, muffins. An hour later the entire menu was different, even the pictures behind the counter had altered.

Now burgers, wraps, hot boxes, salads and even a turkey curry were on offer.

The large open area in front of the counter is still recognisably a fast food joint, with its open floor space, counter and neon food pictures, like a train station at rush hour, but upstairs was at least nicely decorated and fun, lots of people eating salads with their iPads for company.

It’s an ‘eat on your tray’ kind of set up, and there is a constantly changing specials board to keep the regulars interested.

So we ordered and carried our chosen lunch upstairs – super salad with avocados, broccoli and quinoa, bursting with peas and feta, grilled halloumi wraps with burger gherkins and sauce, pots of chicken with mint, Leon baked fries with aoli, which were more like a waffle, the chicken burger, crushed pea salad and meatball hotbox.

The halloumi wrap for your information was 531 calories, priced £4.75 and came with Cos lettuce, baby tomatoes, parsley, mint, aioli and sweet chilli jam.

We tucked in. Heartily. Happily. Vindicated. Smug.

Then cake and coffee and great cake – a must after so much healthy eating. There was nothing virtuous about the chocolate orange brownie – it was rich, dark, filling and utterly delicious.

The small, round pecan pies were less treacly than expected and a bit spartan, but the millionaire’s shortbread, if a rebuke on the cholesterol chart, won big on the tummy front. Plus great coffee.

We were all full to bursting, Leon perfectly bridging that difficult transition between a sit down meal and a stop gap.

And as we emerged, and smelt the fat echoing from the dated burger joint, it was like crossing a time zone between the past and the future.

And let’s face it, it’s time for a change.

Anyone interested in recreating Leon’s wholesome snacks, can do so at home with the help of a recipe book, Leon – Happy Salads.

The book sees Leon authors Jane Baxter and John Vincent bringing together 100 recipes for fresh, vibrant, delicious salads that will have you feeling healthy and happy.

Divided into chapters that include Classics, Naturally Fast, Salads for Friends, Family Salads and Lunchbox, the book contains salads for all tastes and all occasions.

It costs £15.99 from johnlewis.com or all good booksellers.