"What's a cannibal's favorite…

“Kate and Sidney pie” is another way of saying “steak and kidney pie” in the United Kingdom. A popular riddle is:

Q: What’s a cannibal’s favorite meal?
A: Kate and Sidney pie.

The joke was published in Harry Hill’s Whopping Great Joke Book (2008) by Harry Hill.

Wikipedia: Harry Hill
Harry Hill (born Matthew Keith Hall; 1 October 1964) is an English comedian, author and television presenter. He has narrated You’ve Been Framed since 2004, and hosted Harry Hill’s TV Burp for eleven years, from 2001 to 2012. A former medical doctor, Hill won the Perrier Award for Best Newcomer at the 1992 Edinburgh Fringe Festival, and began his career in radio and television comedy with the radio series Harry Hill’s Fruit Corner.

Google Books
Harry Hill’s Whopping Great Joke Book
By Harry Hill
London, UK: Faber and Faber Limited
2008
Pg. ?:
What’s the cannibal’s favourite meal? Kate and Sidney pie.

1 May 2009, Daily Mail (London, UK), “What is a cannibal’s favourite dinner? Kate and Sidney pie: As Harry Hill scoops another BAFTA, his very best gags,” pg. 60:
COMEDIAN Harry Hill this week won a BAFTA for Best Entertainment Performance for the second year running—beating Jonathan Ross, Stephen Fry and Ant & Dec.

Twitter
phil walters 
@philwalters
What is a cannibal’s favourite dinner…......Kate and Sidney pie. (thanks to Harry Hill)
4:49 AM - 1 May 2009

18 November 2009, The Sun (London, UK), “Have a Laugh!,” pg. 20:
WHAT is a cannibal’s favourite meal? Kate and Sidney pie.

Twitter
Philip Beckett
@norwich_broker
Oh by the way What to cannibals enjoy to eat - Kate and Sidney Pie. Come on you know you love it.
10:57 AM - 18 Nov 2009

Twitter
richut
@twitchut
What’s a cannibals favourite meal? Kate and Sidney pie.
3:36 PM - 21 Mar 2012

Twitter
Tie ping
@alecmaynard
Cannibals favorite meal, Kate & Sidney pie
5:28 PM - 7 Jun 2012

Twitter
💕 LadyLeveret © ™ 💕
@LadyLeveret
A cannibal went into a butcher’s shop. He said “I’ll have a pound and a half of Kate and Sidney”!
12:34 PM - 3 Dec 2012

Twitter
Sian- Enetia Hull
@SianEnetiaHull
What is a cannibals favourite meal?
Kate and Sidney pie….
WAHHHHHHH.
5:43 AM - 13 Apr 2013

Twitter
Dan Rhodes
@DanRhodes101
Replying to @rblandford
@rblandford It’s not P.C. to make jokes about cannibals these days. They’re very touchy - you can’t even tell the ‘Kate & Sidney Pie’ one.
11:44 AM - 10 Feb 2015

Twitter
Bob Swanston
@SwanstonRobert
#badjokethursday
What’s a cannibals favourite meal?
Kate & Sidney pie.
5:39 AM - 28 Mar 2019

“What’s a cannibal’s favorite meal?”/“Kate and Sidney pie.”