It's a direct legacy of the Dutch East Indies — Dutch-Indonesian families who resettled in cities like The Hague after Indonesian independence brought the recipe with them, and it's stayed a snack-bar staple ever since.
A thin wrapper is filled with seasoned vegetables, beansprouts and sometimes meat, rolled tight, and deep-fried until the outside shatters when bitten. Snack bars across Zuid-Holland, particularly The Hague with its large Indo-Dutch community, sell them alongside standard Dutch fried snacks.