Begin by bringing a large pot of salted water to a boil. Once boiling, add the rotini pasta and cook according to package instructions until al dente, approximately 8–10 minutes. Drain the pasta and rinse under cold water.

In a large mixing bowl, combine the cooled pasta, cubed sharp cheddar cheese, sliced mini dill pickles, and finely chopped red onion. Toss to evenly distribute the ingredients.

In a separate bowl, whisk together the mayonnaise, sour cream, and dill pickle juice until smooth. Add the freshly chopped dill, salt, and pepper, stirring until incorporated.

Pour the creamy dressing over the pasta mixture and gently toss until well coated.

Cover the salad and refrigerate for at least 2 hours to allow the flavors to meld together. Stir before serving.