Cook the pasta in a large pot of salted boiling water for 8-10 minutes until al dente, then drain and rinse with cold water.

Transfer the cooled rotini to a mixing bowl and combine with dill pickle juice; let sit for 10 minutes.

Chop the dill pickles, cube the cheese, and finely dice the onion.

After the pasta has soaked, drain it again and add the chopped ingredients; gently fold together.

Prepare the dressing by mixing mayonnaise, sour cream, pickle juice, dill, salt, and pepper.

Pour the dressing over the pasta mixture and stir until well coated.

Cover and refrigerate for 1-2 hours before serving.