Cook the rotini pasta in a large pot of salted boiling water until al dente, about 8-10 minutes. Drain and rinse under cold water to cool.

In a large mixing bowl, combine the cooled pasta, cherry tomatoes, mozzarella cheese, black olives, red and green bell peppers, and red onion.

Pour the Italian dressing over the pasta mixture and toss until everything is well coated.

Season with Italian seasoning, salt, and pepper, then add the chopped fresh parsley and toss again.

Cover and refrigerate the pasta salad for at least 1 hour to allow the flavors to meld together.

Before serving, give the salad a quick stir and adjust the seasoning if necessary.