Cook the pasta: Bring a large pot of salted water to a boil. Add the rotini pasta and cook according to package instructions until al dente. Drain and rinse under cold water to cool.

Prepare the vegetables: While the pasta cooks, halve the cherry tomatoes, slice the black olives, dice the green bell pepper and cucumber, and finely chop the red onion.

Combine ingredients: In a large mixing bowl, combine the cooled pasta, cherry tomatoes, black olives, green bell pepper, cucumber, red onion, and fresh basil.

Add dressing: Pour the Italian dressing over the pasta and vegetables. Toss gently to ensure everything is evenly coated.

Season: Add salt and pepper to taste, then sprinkle with grated Parmesan cheese. Toss once more to combine.

Chill: Cover the bowl and refrigerate for at least 30 minutes to allow the flavors to meld. Serve chilled.