Begin by boiling a large pot of salted water over high heat. Once boiling, add the elbow pasta, cooking it according to the package instructions until al dente, approximately 7-9 minutes. Drain the pasta in a colander and set it aside.

After straining the pasta, rinse it under cold water to halt the cooking process and cool it down. In a large mixing bowl, combine the warm pasta with half of the dill pickle juice, tossing well. Allow this mixture to sit for about 5 minutes. Drain off any excess liquid.

In a separate bowl, whisk together the mayonnaise, sour cream, the remaining dill pickle juice, Sriracha, salt, black pepper, and chopped fresh dill. Blend these ingredients until the dressing is smooth and creamy.

In a large serving bowl, add the prepared pasta, diced cheddar cheese, sliced pickles, finely chopped onion, and remaining fresh dill. Gently toss these ingredients together using a spatula.

Pour the creamy dressing over the pasta mixture and fold gently to coat all the ingredients thoroughly. Avoid breaking the pasta or pickles.

Cover the salad and refrigerate for at least 4-6 hours, or ideally overnight. When ready to serve, stir gently and add a splash of extra dressing if desired for freshness.