The phrase comes from Dutch Limburg dialect humour, where mixing a made up price like 10tje 50 with a soggy sandwich creates an instantly quotable nonsense line. It circulated as a short shareable voice clip rather than as a song or film quote, which helped it fit soundboards and chat replies. Its appeal stays local and specific, so people outside the dialect still use it precisely because it sounds confident, familiar and unexplained, turning an ordinary price or food mention into a meme reference.