Old school military slang for "Kitchen patrol," e.g.,
pulling kitchen duty, usually as punishment for some minor offense. Peeling a mountain of spuds was the usual visual associated or serving up flopping patties of glop on trays held forth by worn out G.I.s. Often considered an effeminizing punishment because you had to wear an apron and it took you away from the true manly work of war.
"Where's Allen, Man? We got to get up the road."
"Old lady saw lipstick on collar, Man, or some such shit. Didn't kick his ass out but she got him on K.P. permanently. I think his riding days are over."