When the chef with the most Michelin stars in the world is asked to oversee the creation of the world’s biggest vat of mashed potatoes, there is no place for industrial-sized mixers or short cuts.

Because executing Joël Robuchon’s recipe for perfect mashed potatoes requires old-fashioned tools like a potato mill and lots of elbow grease.

Over the weekend, Robuchon and a team of 200 student apprentices in France entered the Guinness World Records for creating a vat of mashed potatoes that weighed in at 1,042 kg in under six hours. The feat was to help amusement park Le Futuroscope in Poitiers celebrate its 25th anniversary.

But instead of throwing potatoes into a giant mixer, volunteers were tasked with making individual batches in regular casseroles atop hot plates, grinding the potatoes in a mill and mixing the purée by hand, all of which was then decanted into a huge holding vat.

In total, it took 800 kg of potatoes – Rattes du Touquet to be precise – 250 kg of local butter from Poitou-Charentes and 300 liters of milk to prepare.

The finished product was then handed out to park visitors. Watch the making of the record-breaking potatoes below (in French).