Step 1

Bring a large pot of salted water to a rolling boil. Stir in the pasta, and cook according to the package directions.

Step 2

Drain the pasta in a large strainer, and run it under cold water (gently stirring) to stop all of the pasta from continued cooking. Continue until all the pasta's cooled to the touch. Set it aside to drain completely.

Step 3

In a large mixing bowl, whisk together the remaining ingredients, except for the celery and onions. Whisk until smooth. If the mixture's too thick, add a tablespoon or two of water.

Step 4

Season the sauce as needed with additional salt & pepper. Add the pasta, onion, and celery to the pot and toss gently to coat.

Step 5

Serve the macaroni salad immediately, garnished with fresh parsley- if desired.