After selling out at his Notting Hill Carnival jerk-chicken stand, in 2007 he took the secret sauce recipe to the BBC2 show Dragons’ Den. Roots says that he remembers waiting with a man called John, who had invented a horsewhip with a wing mirror, and William, who was looking for cash to expand a business selling clothes dryers that worked in the rain.

Roots was asking for an investment of £50,000. When his name was called, he says, ‘it was like I was being introduced onstage’, so he climbed the stairs,with just £20 in his pocket, his dreadlocks loose in a black suit and polka-dot tie, his acoustic guitar slung on a shoulder, and sang the delights of Reggae Reggae Sauce, so called ‘because it puts music in your food’. As he stood in front of the millionaire investors, where hundreds of flailing entrepreneurs had, variously, wept, sweated and pitched a whole host of ideas, some successfully, and others not so successfully to gain the investment, he sang his gentle little song, and the dragons began to tap their feet. ‘Levi Roots,’ asked Theo Paphitis. ‘Is that your real name?’ ‘No,’ Roots replied. ‘It’s Keith.’

After tasting the jerk chicken, Peter Jones and Richard Farleigh bought 40 per cent of his Reggae Reggae business. ‘Rastafari fixed it,’ Roots says. ‘Jah knows, the whole episode was unbelievable.’ Within weeks his sauce was on the shelves of Sainsbury’s. It became their fastest-selling product, outselling Heinz tomato ketchup in its first year.

Growing up in Britain, in the 1970s, Roots says, ‘I couldn’t escape from being a ghetto kid.’ He joined the Coxsone Sound System as a teenager, writing songs in a Brixton squat, and travelling dance halls with his records. ‘I played in front of 50,000 people with James Brown. But life in Brixton back then was tense. The Sus laws [the stop-and-search law that permitted a police officer to act on suspicion] made sure of that.’ Aged 15 he was sent to Pentonville prison for six months, charged with assault on a police officer. In 1986, police raided the youth club he ran, and he was sent down again for possession of drugs. ‘Lying on my prison bed I did my thinking. I left behind Keith Graham, and I became Levi Roots. I decided to do good.’ Keith still lurks though.

‘Keith, now, is my quiet, serious side,’ Roots explains, as he fries slices of plantain in vegetable oil. ‘Keith is the guy you photographed in the market. He’s the one who does the serious faces. Keith was the one sweating at the end of Dragons’ Den, while Levi is the extrovert, the smiling guy you see on telly. But Keith is sort of famous too – on Facebook apparently, I’m king of the Keith society, over Keith Moon and Keith Chegwin.’

Fast forward three years to May 2010 and Peter Jones who bought out Richard Farleigh for a little more than he originally invested, as the latter didn’t feel able to be able to spent time working on the business in the early stages, is now working with Roots to launch the latest range of chilled Caribbean meals which ‘bring the sunshine of the Caribbean to your table, providing a tasty alternative to any mealtime’.