Well, they have always been around. My earliest memory OF tv chefs, is of a chap Called Philip Harburn, stout fellow .....striped apron, Tall Chefs Hat and a dark 'pugwash' style beard and plummy accent all round good cove ! He was a real celibrity in those days just like his contemporaries are these days. He would also be found advertising I think....and I am not too sure here Paxo stuffing.
What became of him I don't know he had his 15 minutes of fame and faded from our screens with the little 'white dot'.
There was of course THE mega stars of TV cooking Dear old Fanny and Johnny, and in DIY Barry Bucknell and the fifties answer to Titmarch was of course the late Percy Thrower.....so nothing new except the times really.