If I remember correctly, it's in the "blessing of the animals" episode of The Vicar of Dibley where the Reverend(?) Geraldine and the verger, Alice Tinker, have a conversation about "I can't believe it's not butter" that is one of the funniest routines I have ever heard on television. It ranks right up there with classic comedy routines like Abbott and Costello's "Who's on First?" Track it down. It's an absolute howl.

Don Firth