If argula has roots attached, cut them off. Fill the sink with cold water and toss the arugula for a few minutes to clean. Spin - dry the leaves and place them in a large bowl. In a small bowl, shixk together the lemon juice, olive oil, salt and pepper. Pour enough dressing on the arugula to moisten. Toss well and place the salad on individual plates. With very sharp knife or a vegetable peeler, shave the Parmesan into large shards and arrange them on the argula. YUM!