"Mistakenly thought of as French rather than a Belgian invention, pommes frites, also known as pataten and frieten in Belgium, are lengthways sliced Bintje potatoes that have been double fried in horse or ox fat. They traditionally come served in a paper cone, and are usually only sprinkled with lots of salt, but nowadays will also be topped with some kind of sauce, typically one that is mayonnaise-based!"
Thanks to Nikibakes for the tasty recipe!