The name has nothing to do with truffles: it comes from Occitan 'trufa', the Auvergne word for potato.
Sliced potatoes fried with garlic, then stirred with fresh, unsalted tomme until it melts into long strings; in summer it is dished out at Cantal evening country markets (marchés de pays).
Why it's made this way: It was the food of Cantal herders in their stone mountain huts (burons), who paired stored potatoes with the fresh tomme they made from Salers and Cantal milk.