In large mixing bowl, stir in the onion, celery, parsley, lemon juice, mustard, garlic powder, and cayenne. Let them sit while pasta is cooking.

Cook pasta per the instructions on the box.

Once pasta is drained quickly add to the bowl retaining as much of the pasta water on the noodles so they remain moist.

Once pasta is cooled or close to room temperature, add in the mayo and let stir.

Season with salt and pepper to taste. Best served cooled.