Bring a pot of generously salted water to a boil. Add the elbow macaroni and cook according to package instructions until al dente. Drain well and rinse with cold water to stop the cooking process; set aside.

If you haven't already, hard-boil your eggs. Once cooked, transfer them to an ice bath to cool completely. Peel the cooled eggs and dice them into small pieces.

In a large mixing bowl, combine the cooked and drained pasta, diced hard-boiled eggs, diced celery, diced red bell pepper, sliced green onions, and minced fresh parsley. Stir gently to combine all the ingredients.

Prepare the dressing: In a small bowl, whisk together the mayonnaise, whole-grain mustard, red wine vinegar, salt, and black pepper until smooth. Taste and adjust seasonings as needed for your preference.

Pour the dressing over the pasta mixture in the large bowl. Mix thoroughly to ensure all ingredients are evenly coated. Pasta will continue to absorb dressing as it chills, so you may make an additional half batch of dressing if you prefer a wetter salad. Taste again and adjust salt or add a tiny pinch (0.125 teaspoon) of cayenne pepper for a faint kick, if desired.

Cover the bowl and chill the Deviled Egg Pasta Salad in the refrigerator for at least 1 hour before serving. This allows the flavors to meld beautifully.