Cook the Pasta: Bring a medium pot of lightly salted water to a boil. Add the macaroni and cook until al dente, about 5–7 minutes. Drain and rinse under cold water to stop the cooking and prevent sticking. Set aside.
Make the Dressing: In a small bowl, stir together the mayonnaise, sour cream, vinegar, relish, mustard, and parsley.
Mix the Salad: In a medium bowl, combine the cooked macaroni and the grated carrots, chopped red bell peppers, chopped celery, and chopped red onions.
Add the Dressing: Pour the dressing over the pasta and vegetables. Stir to combine.Tip: For the best flavor, cover and chill the salad for at least 1 hour before serving.
Notes
Cook pasta al dente: It will continue to soften as it absorbs the dressing.
Chill before serving: Refrigerate for at least 1 hour to let the flavors blend.
Adjust seasoning: Taste before serving and add more salt or vinegar if needed.
Prep ahead: Read the full recipe and Ingredient Notes first, then gather all ingredients before starting.