Cook pasta according to the directions on the box. Drain pasta and let stand under cold running water until completely cooled. Set aside. In a mixing bowl, combine chopped apples and celery; add lemon juice and toss to combine. Set aside. Arrange lettuce on a large serving plate or a large salad bowl. If wet, pat dry the penne pasta and add it to the salad. Top with apple-mixture, walnuts and cheese. Set aside. Prepare the dressing by combining all ingredients in a blender. Blend until creamy and smooth. Drizzle over salad. Taste for seasoning and adjust accordingly. Serve.