I thought so too, and then I remembered where: Terry Pratchett, The Truth:
"...An' then... then I'm gonna get *medieval* on his arse." "How, exactly?" "I thought maybe a maypole," said Mr. Tulip reflectively, "An' then a display of country dancing, land tillage under the three-field system, several plagues, and if my --ing hand ain't too tired, the invention of the --ing horse collar."
"What now? Let me tell you what now. I'm gonna call a couple of hard, pipe-hittin' niggers to go to work on the "homes" here, with a pair of pliers and a blowtorch. You hear me talkin' hillbilly boy? I ain't through with you by a damn sight. I'm gonna get medieval on your ass."