The religious correspondent on the Sky News morning programme yesterday referred to him as Bishop senˈtɑːmuː. But, as those who consult LPD or the Oxford BBC Guide to Pronunciation will know, his own preferred pronunciation is ˈsentəmuː. (Those who consult Wikipedia, on the other hand, will find there the implausible ˈsɛntɑːmuː. Perhaps one of you will now correct it.)
The Archbishop has given us an easy way to remember the correct pronunciation of his name. He asks us to imagine three cows standing in a row. Each cow moos. On the left we have a left moo, on the right we have a right moo, and in the centre we have a centre moo. And he’s like the centre moo, ˈsentəmuː.
(Sorry this doesn’t work for AmE or even for the Scots.)