The vials of nanobots intended for a contained science lab ended up at a pasta factory. The overzealous IT student working at the factory through school thought they were for cleaning and he programmed them to clean up food waste. Instead they spread over the planet, destroying food everywhere.
Still slaves to their programming however, they were reprogrammed to reconstitute raw materials into edible, noodly substances, inadvertently solving world hunger.
Unfortunately it didn’t taste good, until a culinary student programming to pay his way through school reprogrammed some of the bots to create flavor, and Greygu pasta sauce was invented.