Cook the pasta as directed on the package. Once done, drain and rinse with cold water to stop the cooking process and remove excess starch.
Place the chopped onions in a small bowl, cover with cold water, and let them sit for 5 minutes to mellow their sharp taste, then drain.
In a large salad bowl, whisk together the sour cream, mayonnaise, mustard, cider vinegar, salt, and pepper to create the dressing. Add honey if you prefer a touch of sweetness.
To the bowl with the dressing, add the cooked macaroni, drained onions, bell pepper, celery, radish, and pickles, if using. Stir until everything is well coated with the dressing. Taste and adjust seasoning with more salt and pepper if needed.
Store in the fridge for at least 2 hours so that the flavors have time to meld. If possible and for best flavor, take the salad out of the fridge 30 minutes before serving.