What is "porilainen"

Porilainen is a sandwich and street food dish in Finnish cuisine made from white bread and a half-inch slice of thick sausage. In addition, porilainen usually contains diced sweet onion, chopped pickled cucumber, ketchup, mustard, and in some cases mayonnaise. Porilainen is a combination of a hamburger and a hotdog, and the name may be a twist on the Finnish for "burger" (purilainen), but it also means a person from Pori.