'One Pair of Eyes: Dreamwalkers' presented by Idries Shah, 19th Dec 1970, BBC Television (UK).
The documentary is about Shah rather than the animated film, but there is a short interview with Williams. It's possible that a clip or clips from the original Nasrudin film were included. The transcript may show a segment about bread.
This is very possibly the 1969 BBC doc referred to.
http://64.233.167.104/search?q=cache:YXTX-HF29bcJ:freehost19.websamba.com/sarmoun/onepair.htm+%22richard+williams%22+nasrudin&hl=en
Picture of the front cover of a book on Mulla Nasrudin. The book is opened to reveal Nasrudin sitting on his donkey, facing the wrong way].
NARRATION: Another traditional means of passing on the fruit of experience is a highly advanced form of story with many levels of understanding. Hundreds of them are about Mulla Nasrudin, a sort of Oriental Everyman. A[n animated] film of him is in the making by Richard Williams. Here, Nasrudin is hauled before the king, accused of heresy:
Courtier: He has admitted going around saying 'Such wise men as these are ignorant, irresolute and confused.'
King: Nasrudin, you may speak first.
Nasrudin: May I ask the learned ones a question?
King: Proceed.
Nasrudin: Oh wise men, what is bread?
Wise man: Bread? Stupid question.
King: Go on.
Wise men, in succession (1): Bread is a substance which is for the purpose of nourishing people. It is in fact a food.
(2): Bread is a compound of flour and water mixed at a certain ratio and subjected to a certain heat.
(3): It is a blessing which descends as manna from the heavens. It is a gift from God, notwithstanding man's iniquity and undeserving state.
(4): Bread is a substance from which man draws nutriment.
(5): Throughout the ages, servants and sages have sought the answer to this question. But still, it has to be admitted that nobody really knows.
Nasrudin: Your Majesty: how can you trust these men. Is it not strange that they cannot agree on the nature of something they eat every day, yet are unanimous that I am a heretic?
NARRATION: Richard Williams has been living with Nasrudin for five years.
WILLIAMS: With me, I just found them brain breakers. I was going around heavily about it, then I kind of just started to like them. I found that they'd pop up like people here and you'd say 'That's like….' 'Oh, good heavens….' And you'd quote the punch-line which relates to a situation [in your own life] and gradually you'd like it more and more. Whereas at first you'd say 'Mulla Nasrudin? Whatever's that?' And then [later] you don't get rid of it - you don't wear it out.
SHAH: That's the extraordinary thing about it [Nasrudin stories] it has durability. It doesn't wear out. Why not? Normally people get fed up with jokes and wisecracks.
WILLIAMS: And everybody says, you know, five years you've been working on this thing. Surely, surely you can't stand it: the same thing every day. I say 'Never!' I get worn out on a one month job - commercial job, or something - but not on Nasrudin.
SHAH: It is very, very strange.
[Shot of cover of The Pleasantries of the Incredible Mulla Nasrudin by Idries Shah].
SHAH [narrating]: The Nasrudin tales which I have published have proved their worth in ways in which few scientists would have imagined. Doctor John Kermish (?) specialised in choosing certain types of inventive brain for the American Rand Corporation. This is the original Think Tank, pioneering new ways of thought to solve industrial, commercial and social problems. He made a text book out of the Nasrudin stories.
KERMISH: The one which pops most readily into mind is the one I remember where Nasrudin is looking outside his house for something. Someone asks what he's looking for and he says his key. They ask if he lost it there and he says no, he lost it inside the house, but there's more light outside, so it's better to look there.