Bow ties or small shells also work. If using bow ties, mayonnaise may have to be increased by 1/4 to 1/2 cup.
Short on time? Still tastes great after chilling for only a couple hours. Mix the dressing first, while the pasta water comes to a boil, and refrigerate. Chop the onions and celery while the pasta is cooking, and add to the dressing in the fridge. When pasta is cooked, drained and, cooled, add to the dressing. Chill until serving time.