Step 1: Cook the pasta according to package directions until al dente. Drain and rinse thoroughly under cold water to cool, then set aside.
Step 2: While the pasta cooks and cools, finely chop the dill pickle slices, red onion, and celery stalk. Aim for small, uniform pieces for the best texture and distribution.
Step 3: In a large bowl, whisk together the mayonnaise, sour cream, Dijon mustard, and dill pickle juice until completely smooth and well combined. Fold in the chopped fresh dill.
Step 4: Add the cooled pasta, chopped dill pickles, finely diced red onion, and finely diced celery to the bowl with the dressing. Gently toss until all ingredients are evenly coated.
Step 5: Season the salad with salt and freshly ground black pepper to taste. Start with a pinch and adjust as needed. Stir gently once more.
Step 6: Cover the bowl and refrigerate the pickle pasta salad for at least 1 hour, or preferably longer, to allow the flavors to meld and deepen. Stir again before serving.