In the 30 years since its UK supermarket debut, pesto has captured Britain’s heart, becoming a go-to saviour of the midweek meal. And not just in the classic pesto alla genovese form. From chilli-spiked to truffled incarnations, pesto has come a long way since 1991. “Start with the premise that it contains herbs, nuts, cheese and oil,” says George Leigh, chef at the Birmingham pizzeria Otto. “Then pick the herb or cheese and adjust everything.