Is there any evidence that the origin of "pièce de résistance" lay in artillery? A native French speaker once told me he believed the term for the crowning culinary creation of a meal had its origin in the most impressive defensive cannon a fort boasted.
I managed to find recent usage in an English work along those lines here:
Though the scope for modern earthworks at Skipton was limited, considerable pains were taken to remount the artillery. Guns were hoisted up to the top of a number of towers, but the pièce de résistance was at the south east corner of the fortress. Here a 'great mount' was erected and the biggest gun, the two ton demi cannon, was hauled up onto the platform. This mount alone cost £8 to build, but it was money well spent for, when the Parliamentarians first approached in 1643, they were kept so far back from the walls by the thunder of cannon that they were unable to inflict any damage.
(Bull, Stephen, The Furie of the Ordnance: Artillery in the English Civil Wars. Boydell & Brewer Ltd, 2008)
However, I cannot prove that this hearkens back to some original usage; it may just be the author's own play on words, since a "piece" can refer to a cannon in English even now. (And apparently it may be used thus in French as well.)
English etymology sources I consulted are vague on the origin, beyond the obvious French attribution:
1831, from French pièce de résistance, originally "the most substantial dish in a meal." Lit. "piece of resistance;" there seems to be disagreement as to the exact signification.
Some believe that the translation of the phrase is “the piece with staying power”, though there is some discussion about that interpretation.
At the moment, I'm inclined to suspect that the term did indeed emerge similarly to the English phrase "bringing out the big guns". (For one thing, "the piece with staying power" seems rather less than convincing -- why would describing a consumable as having "staying power" catch on? Is "résistance" even idiomatically used that way in French?)
However, I'm not fluent in modern French, much less French of 18th C. or earlier, and it'd be nice to have something more substantial to back this up and take it out of folk etymology. Is there any firmer evidence to support the argument in favor of an origin in cannonry? (Or, conversely, good reason to doubt it?)