A countrywide boom in sales of skewers, prunes and sweetened condensed milk has been attributed to celebrity chef Delia Smith.

The first episode of Smith’s television show How To Cook was aired on BBC2 on Tuesday night and, according to UK supermarket group Asda, the “Delia effect” can prove to be a lucrative one for retailers.

Asda told the Mirror: “Her prune recipe really got our customers going.

“Sales of prunes were up by 30%, sweetened condensed milk up 27% and skewers up 35%.”

In the episode, Smith made a sticky prune and date cake, which she tested with a skewer.