Even in the cheapest Greek restaurants they do use leg of pork rather than a cheaper cut, because it is so much better.
Cut the pork into little cubes and sprinkle liberally with oregano, lemon juice and pepper. Allow it to soak up these flavours for a couple of hours, turning the cubes over from time to time. Thread the cubes on skewers and shake off as much lemon juice as you can. Bru