A French kitchen pun is:
   
Q: What’s the result of tossing a live grenade into a French kitchen?
A: Linoleum Blownapart.
 
The Napoleon Bonaparte/Linoleum Blownapart joke has been cited in print since at least 1982.
 
   
Wikipedia: Napoleon
Napoléon Bonaparte (/nəˈpoʊliən, -ˈpoʊljən/; French: [napɔleɔ̃ bɔnapaʁt], born Napoleone di Buonaparte; 15 August 1769 – 5 May 1821) was a French military and political leader who rose to prominence during the French Revolution and led several successful campaigns during the Revolutionary Wars. As Napoleon I, he was Emperor of the French from 1804 until 1814, and again in 1815. Napoleon dominated European and global affairs for more than a decade while leading France against a series of coalitions in the Napoleonic Wars.
 
16 December 1982, Pittsburgh (PA) Post-Gazette, “What to give to the unemployed” by Joe Browne, pg. 27, col. 3:
Kitchen crisis
This was passed on by a co-worker who doesn’t want to be identified publicly with it: What do you call a Molotov cocktail thrown into the kitchen of a French restaurant? Give up? It’s Linoleum Blownapart. Oh, my.
           
2 March 1983, Chicago (IL) Sun-Times, “Kids’ jokes about food are a laughing matter” by Kim Upton, sec. ?, pg. 1:
What do you get when you throw a hand grenade into the kitchen?
Linoleum blown apart.
 
18 March 1983, Salina (KS) Journal, “What Now?” by John Schmiedeler, pg. 3, col. 1:
Worst-joke-of-the-week, courtesy of Loyde Davis, 2055 Mission Road:
 
“What do you get when a hand grenade explodes in the kitchen?”
“Linoleum Blownapart!”
 
Sorry, it’s even worse in print than when Loyde tells it.
 
8 April 1983, Arkansas Gazette (Little Rock, AR), “Winnie the Pooh” comic strip, pg. 7B, col. 1:
SO THE GUY SAYS “NAPOLEON BONAPARTE! I THOUGH YOU SAID ‘LINOLEUM BLOWNAPART’!”
 
Google Books
November 1983, Boys’ Life, “Think & Grin,” pg. 89, col. 3:
Marie: What do you get when you thrown a bomb in a French kitchen?
Antionette: Linoleum blown apart. — Joshua Doty, Bridgeville, Pa.
 
10 December 1984, Trenton (NJ) Times, “Give the gift of food this Christmas” by Frank Tyger, pg. A2, col. 1:
My friend Bill McGuire of Ewing Township asks: “What do you get when you cross linoleum with dynamite?”
   
“Linoleum Blown-apart.”
 
Google News Archive
6 April 1990, Milwaukee (WI) Journal, “Tongue oil: Pun crusaders enjoy a big knight out” by Stephen Maersch, Green SHeet, pg. G1, col. 4:
Crosbie presented Punster of the Year honors to Bob Thaves, creator of the cartoo nstrip “Frank and Ernest,” which appears in the Milwaukee Sentinel. Thaves likes to work puns into his strips. Sample he offered: “Pierre tossed a grenade into the kitchen, and you know what he got? Linoleum blown apart.”
   
Google Books
He Who Laughs Lasts
By Shawn Lovley
Lincoln, NE: iUniverse.com
2001
Pg. 139:
A student was reading a book about the history of Europe, and learned that the guy who threw a grenade into a French kitchen was named “Linoleum Blownapart.”
   
Google Books
Over 1500 Fantastic Jokes
By Guy Campbell and Paul Moran
London: Dean
2002
Pg. 244:
What do you get when you toss a hand grenade into a French kitchen?
Linoleum blownapart!
 
Google Books
Blonde Walks into a Bar:
The 4,000 Most Hilarious, Gut-Busting Gags, One-liners and Jokes
By Jonathan Swan
Berkeley, CA: Ulysses Press
2008
Pg. ?:
What do you get when you roll a hand grenade across a kitchen floor?
Linoleum blownapart!
 
Twitter
Andy Lopata
‏@AndyLopata
Terrorist in paris threw grenade through a kitchen window!- The result was linoleum blown apart…..(I know I know. Coat already on)
4:11 PM - 7 Feb 2009
 
Twitter
Shamrock
‏@Shambo
BREAKING NEWS: A hand grenade that was thrown into a kitchen in France resulted in linoleum blown apart.
5:32 PM - 22 Feb 2009
 
Google Books
The Mammoth Book of Really Silly Jokes:
Humour for the whole family
By Geoff Tibballs
London: Constable & Robinson, Ltd
2011
What emperor do you get if you throw a hand grenade into a French kitchen?
Linoleum Blownapart.
     
Google Books
Once Apun A Time:
A Rich, Historical and Sometimes Earthy Collection of Puns
By Robin Leech
Victoria, BC: FriesenPress
2015
Pg. ?:
A grenade thrown into a kitchen in France would result in Linoleum Blownapart.
 
reddit
What’s the result of tossing a live grenade into a French kitchen?
submitted July 27, 2016 by PlatoDescartes
Linoleum blown apart.