Undercover chef Ramsay tricks Delia

6:20am Friday 24th October 2008

Here is Gordon Ramsay posing with a smiling queen of the cooks Delia Smith - who is blissfully unaware of who he is due to a cunning disguise.

Ramsay, wearing glasses and sporting darker, thinning hair, became unrecognisable so he could pretend to be a punter at Smith's Food and Wine Workshop at Norwich City Football Club.

He went deep undercover to infiltrate schools run by some of the nation's best-known celebrity chefs to find out what his rivals are up to.

He later revealed his identity to Smith, who had been unaware that one of the world's most famous chefs and loudmouths had been right under her nose.

Other celebrities who have donned disguises to play pranks include Ant and Dec and Charlotte Church.

Ramsay's latest challenge is said to be "the first of many surprises", when he returns to screens for Gordon Ramsay: Cookalong Live on Friday at 9pm on Channel 4.