1. Cook the Pasta: Bring a large pot of salted water to a rolling boil. Add the rotini pasta and cook according to package directions until al dente. This usually takes about 10-12 minutes. You want the pasta to be tender but still have a slight bite.

2. Drain and Cool the Pasta: Once cooked, drain the pasta thoroughly in a colander. Rinse it with cold water to stop the cooking process and cool it down quickly. This prevents the pasta from getting mushy and helps the salad stay fresh. Let it drain completely.

3. Prepare the Dressing: While the pasta cooks, whisk together the mayonnaise, sour cream, olive oil, white wine vinegar, Dijon mustard, minced garlic, salt, and black pepper in a large bowl. Stir until the dressing is smooth and well combined.

4. Combine Salad Ingredients: In the same large bowl with the dressing, add the cooled pasta, shredded or diced cooked chicken, halved cherry tomatoes, and drained mozzarella pearls.

5. Add Fresh Basil: Gently fold in the chopped fresh basil leaves. The vibrant green basil adds a burst of fresh flavor and color to the salad.

6. Toss Everything Together: Carefully toss all the ingredients until everything is evenly coated with the creamy dressing. Make sure the tomatoes and mozzarella are distributed throughout the pasta.

7. Chill Before Serving (Optional but Recommended): For the best flavor, cover the bowl and refrigerate the pasta salad for at least 30 minutes to allow the flavors to meld. This also ensures it is nicely chilled for serving.

8. Garnish and Serve: Before serving, give the salad another gentle stir. Drizzle with balsamic glaze, if desired, for an extra layer of flavor and a beautiful presentation.