Between pieces of plastic wrap, gently pound pork with flat side of meat mallet until very thin. Place in glass baking dish. In small bowl, mix dressing, lime peel and oregano. Spread over pork; turn pork to coat. Let stand while heating contact grill.
Heat closed medium-size contact grill for 5 minutes. Position drip tray to catch drippings. Place pork on grill. Close grill; cook 5 to 6 minutes or until no longer pink in center. Meanwhile, place cheese on cut sides of roll bottoms; top with ham, pleating to fit. Spread mustard and pickle relish on cut sides of bun tops. Place grilled pork on ham; place roll tops, relish sides down, on pork. Press down firmly on tops of sandwiches (sandwiches are thick).
Carefully wipe off grill plates; spray with cooking spray. Place sandwiches on grill. Carefully close grill so tops of rolls don’t slip off sandwiches. Gently press top of grill until sandwiches are compressed. Cook 3 to 4 minutes or until rolls are toasted and cheese is melted.