The French P-38 Can Opener.
Can opener, scraper, screwdriver, chisel, pick, the tool of a hundred thousand uses, “The Greatest Army Invention”, “invented in just 30 days in the summer of 1942 by Maj. Thomas Dennehy at the Subsistence Research Laboratory in Chicago”*, was actually invented 30 years earlier by a Frenchman.
My entire world has been upended. That magnificent piece of American technology is French?
The blog I borrowed this from is interesting in its own right, with posts about the hardware, and the recipes related to field feeding of troops. The 1944 Army biscuit recipe looks pretty promising.