Sheffield’s BOSH! on Extinction Rebellion, the animal products in our mobile phones and their new vegan survival guide

Henry Firth and Ian Theasby – who met at school in Sheffield and go by the name of BOSH! – have produced two best-selling collections of vegan recipes that have gently extolled the virtues of eating 'plant-based' meals.

But now they're taking a different approach with their third book. How To Live Vegan is a guide to surviving – as much as is practicable – without relying on meat, dairy or everyday items containing animal products.

It also delivers some sobering, and timely, messages about the climate emergency, emphasising that for plenty of people veganism extends far beyond the food they eat.

"We're looking a little more in depth at some of the problems we're facing as a society and as humans, and maybe answering the question of 'why?' which we've never really tackled before," says Henry. "It was a bit of a first for us to be talking about that. Up until now it's been all 'how' - how to cook vegan food, and all that kind of stuff."

Ian says the pair felt 'duty bound' to give a detailed account of themselves.

"We've been asked so many times why we are vegan, be it on social media, in interviews or in person. We thought we'd like to put a big answer together in the form of a book."

Henry and Ian, both in their mid-30s, became friends at High Storrs School aged 11 and later moved in together in London where they began making very popular YouTube and Facebook videos demonstrating how to prepare vegan dishes. They were both converted after watching Kip Andersen's documentary Cowspiracy, which argues that animal agriculture is destroying the environment.

Wary of moralising, they say How To Live Vegan performs a fine balancing act.

"I think all the way we were catching ourselves and making sure it was written for the reader and not just from a vegan's perspective," says Henry.

An eye-opening chapter, titled False Friends, lists 'innocent-sounding food items' containing animal products that even BOSH! have been caught out by, forcing the conclusion that a 100 per cent vegan lifestyle is an impossible goal.

Most real ales and some wines are produced using isinglass from fish bladders to refine the alcohol, fresh pasta usually contains eggs and fruit can often be coated with glazing agents made from shellac - created from the secretions of the lac bug.

Outside the kitchen, banknotes are rendered smooth with tallow - animal fat - and a section penned by Henry's fiancee EmJ, a make-up artist, deals with the beauty industry, pointing out that many lipsticks feature the red dye carmine, consisting of crushed cochineal insects.

"It's also interesting to note that your car or even the electronics in your mobile phone are going to be packed with things engineered using animal products," says Henry, who thinks labelling needs to be improved 'across the board'.

"Definitely the onus is on the manufacturer. But the manufacturers are doing what they're allowed to do by the government... so the onus is probably also on regulatory bodies to think about messaging a bit better."

Retailers need to improve too, Ian and Henry believe.

"We've just done a series wandering around supermarkets hunting down vegan products, and despite the plethora of delicious things available, it's still tricky to find good stuff to eat," Henry says.

Fast-food chains, sensing a major shift in attitudes, have begun to cater for the growing number of people following a plant-based diet. KFC is trialling meat-free 'chicken', Burger King has a vegetarian Whopper and Greggs is working on vegan products of all its menu classics - such as steak bakes and pasties - after successfully launching a vegan sausage roll.

"I think it's great," says Henry. "Of course we understand the perspective that people are talking about 'green washing' and actually it's just an excuse for big business to carry on as it currently is, and in part that may be true.

“But if we can shave five, ten, 20 per cent off the impact those large companies are having on the planet by shifting them to what has been proven to be more sustainable forms of food production, that's got to be a good thing in our opinion. It shows people are waking up to veganism being a really positive move."

Ian and Henry both support the activities of campaign group Extinction Rebellion, whose protests have involved blocking traffic and staging 'die-ins' where members lie prone on the ground to simulate being dead.

"For the actual big change that needs to happen in order for us to have any chance of stopping the rising temperature, or calm it from going to catastrophic levels, Extinction Rebellion are exactly the kind of activity the human race needs right now," says Henry.

Given their online videos have reached many millions, there has been talk in the past of a BOSH! television show, but any progress on that front is under wraps for now.

A fourth book is on the way, however. Healthy Vegan will, appropriately, be published just after Christmas, appealing to those bleary from festive indulgence.

Readers can look forward to 'BOSH! food but with less oil, no sugar, less salt and everything worked out with an NHS dietician', says Ian. "It's all bulletproof. I think a book like this hasn't been written before, it's food people actually want to eat that happens to be exceptionally healthy. Usually healthy vegan food is boring salads or ingredients you've never heard of."

BOSH! How To Live Vegan is published on October 3 by HQ. Henry and Ian will be at the Off The Shelf literary festival on Saturday, October 5 for a Q&A and book signing at Sheffield University's Firth Hall. Visit www.offtheshelf.org.uk for details.