Japanese Korokke Pan, or Croquette Sandwich

Korokke Pan, or korokke sando consist of traditional Japanese korokke–potato, or meat and potato, or potato and vegetable–in a long thin bread roll much like a hot dog bun, with shredded cabbage, some combination of sauces likely to contain Japanese Worcestershire and/or Tonkatsu sauce, and is garnished with a sprig of parsley. They are sold in prepackaged form at Japanese conbini, convenience stores like 7-11, which I am told have a much tastier food selection than the 7-11s around here.