Reminds me of the 'Not The Nine O'Clock News' sketch: Watership Down: You've read the book, you've seen the film. Now try the pie!
(
Dick Wonder ₐ wₒₙₖy, wₐᵥy wₒₙdₑᵣ,
Fri 30 Sep 2011, 16:58,
archived)
Version I heard was
Watership Down: You've read the book, you've seen the film. Now eat the cast
(
Sir Tainley Barking Ezekiel 23:20,
Fri 30 Sep 2011, 17:05,
archived)