Photo: The original uploader was PhilFree at French Wikipedia. / Wikimedia Commons · CC BY-SA 1.0
The 'greubons' folded through the dough are crispy leftover pork cracklings from rendering lard — a savory pastry built entirely around a butchery byproduct.
A rich, buttery pastry dough is studded with greubons — crisp bits of rendered pork fat — rolled and baked into a flat, flaky square. Geneva bakeries sell it as a savory grab-and-go snack, often still warm from the oven.
Why it's made this way: It's a classic example of nose-to-tail thrift, turning a rendering byproduct that would otherwise go to waste into a bakery specialty.