the story I was told all my life is that back in 1972 one butcher from my hometown of České Budějovice (that's also where original Budweiser beer comes from) came up with the idea to do it like this, although it is believed he has seen something similar while on vacation in Spain - that's also why it's not only called "sausage in roll" in Czech, but also "pikador" - because you spike the roll onto pointy piece of metal to make room for the sausage inside, just like Spanish pikadors stick their pikes into bulls in corrida while bullfighting