When we last met crisp lover Kevin Harvie he was riding the crinkled edge of a wave of success with the humble sweet potato.

It was 2014 and the Glasgow accountant had managed to land a pretty sweet deal with supermarket giant Tesco after dabbling in the world of snacks.

He began as a hopeful young man in his kitchen, chopping tubers to make his own sweet potato crisps after being let down by his work vending machine.

Kevin, whose mates had by now jokingly begun to nickname him Crisp Boy, had already swapped his regular white potatoes for sweet potatoes in his evening curries as he loved their healthy nutrients.

Convinced other people would like his gluten free sweet potato crisps too, he started cooking and dishing up his own snacks for friends in a variety of flavours.

"I kept practising in my kitchen and people seemed to like them," said Kevin, a former Dundee University graduate.

"I packed in my job as an accountant to make crisps and just ran with it. I just thought - I'm going to be the guy who makes sweet potato crisps."

A year later he signed a nationwide deal with Tesco and had a comfortable expected turnover of £150,000 by the end of the year.

Hectares Sweet Potato Crisps hit the shelves but that is not quite where Kevin's story ends.

Three years on and Kevin has a new crisp on his mind - and it is decidedly puffy.

Spurred on as a father himself to find healthier snacks for his own children, he struck upon the idea of lentil crisps that are not only vegan but gluten free, too.

"We'd had a lot of requests for crisps that are made for families and low in salt and fat," says Kevin.

"We felt puffed crisps were the best way to go. Everyone knows Wotsits and Space Raiders, those kind of puffed snacks but healthier."

Kevin now has his space-themed children's snack called Super Moons, with packets already tested by a lot of youngsters, especially his own.

"If you give an adult something, most people are so polite they'll just tell you they like it, but kids will just spit it straight out," laughs Kevin.

"You won't be under any misconceptions about what they think of it."

Currently in two flavours, salt and vinegar and cheese and onion, the crisps are now available at family places like Crieff Hydro and Lego Land.

He has plans to launch multi-packs of them later in the year for school lunchboxes.

The snack's arrival comes just a few years after reports from university researchers based at the Royal Hospital for Sick Children in Edinburgh revealed child coeliac numbers in Scotland are reaching a record level.

In 2013, when Kevin first began dabbling in crisps, scientists found coeliac disease was affecting six times more children living in Scotland then than it did in 1990.

The genetic disorder is triggered when a virus causes the immune system to attack the lining of the intestine.

Using a mix of corn, lentils and rice, Kevin says his crisps are allergen free and is hopeful children will like them.

Despite his move from sweet potatoes to lentils, he says he has no other vegetable adventures lined up for the near future outside of lentils.

"There's only so much you can do in a day," says Kevin with a laugh.

"With any business you go through ups and downs and it's tough, really tough but there are so many highs as well.

"If you weren't having fun though, it wouldn't be worth it. I'm definitely not quitting and going back to accounting. It's about having the freedom to go and pursue what you're passionate about."