Clean corn, break cobs in half and boil for 7 to 8 minutes. Drain well.
Mix oil, vinegar, mustard, Parmesan cheese and parsley to make dressing. Line a platter with Romaine lettuce leaves. Roll each cob of corn in dressing and place on a lettuce leaf. Drizzle remaining dressing over each corn and sprinkle with a little more Parmesan cheese and parsley. Serve warm or room temperature with lettuce leaf wrapped around corn. Serves 10.