First it was the banana peel, then it was the double-buttered toast, now Nigella Lawson is to trigger a new culinary controversy with one of the most polarising ingredients known to man, woman or child: liquorice. The celebrity chef has turned the third episode of her BBC Two series, Cook, Eat, Repeat, into a hymn to the black chewy substance – its taste, texture, colour and alleged deliciousness as a sauce. Lawson concedes liquorice can be “challenging” and “corrosively salty” – arguably fancy ways of saying revolting – but hails it as a versatile, glorious accompaniment to Basque burnt cheesecake. The episode, to be aired on Monday, follows the formula of two previous shows in singling out an unconventional approach to cooking that seems designed to intrigue and provoke viewers while proving comfort TV. “I have given my liquorice box a bit of an international refit so where shall we go first?” Lawson asks, breaking the news that an idealised lifestyle requires a liquorice box. She unveils silver dragrées from Germany, with a caution: “I love them. They do make my fillings reverberate as I eat them. Maybe it’s worth it.” They are followed by “salty rock stars” from Sweden. “You need to be strong for these. They are corrosively salty.” Then come Dutch bonbons from the Netherlands and extra-strong liquorice pellets from Italy. One of these additions to Lawson’s liquorice “toolbox” provides the key element to the cheesecake sauce, says the advance BBC publicity. The banana skin and cauliflower curry unveiled in the show’s first episode – Lawson poured boiling water over two darkened skins – proved to be social media catnip. She added turmeric and salt to the skins and shredded them with a fork until they resembled “gagh”, which Lawson explained was a Klingon delicacy. The second episode recommendation’s to butter toast twice, and add sea salt after the second buttering, prompted debate about whether this was inspired lockdown indulgence or a form of madness. Liquorice sauce could prove even more divisive. A compound called glycyrrhizin, 40 time sweeter than sugar, gives the root of the liquorice plant its flavour. It is used in cough syrup to mask other ingredients and also used to treat stomach ulcers, herpes, hepatitis and cirrhosis. A Massachusetts construction worker who ate a bag and a half of black liquorice every day for several weeks died after it threw his nutrients out of balance and caused the 54-year-old man’s heart to stop, doctors reported,” the New England Journal of Medicine reported last month.