Bring a large pot of well-salted water to boil. Cook 1 pound rotini pasta according to package directions until al dente, about 1 minute less than recommended. Drain without rinsing.

While pasta cooks, prepare vegetables: halve 1 cup cherry tomatoes, dice 1 red bell pepper and 1 yellow bell pepper, finely dice 1/2 cup red onion, and slice 1/2 cup black olives.

In a large mixing bowl, whisk together 1/3 cup olive oil, 3 tablespoons red wine vinegar, 2 minced garlic cloves, 1 teaspoon Italian seasoning, 1/2 teaspoon salt, and 1/4 teaspoon black pepper.

Transfer warm drained pasta to the bowl with dressing. Toss immediately to coat evenly. Let sit for 10 minutes, tossing occasionally to help pasta absorb flavors.

Add prepared vegetables and 8 ounces halved mozzarella pearls to the pasta. Toss gently to combine without crushing the cheese.

Stir in 1/4 cup chopped fresh basil and 1/4 cup chopped fresh parsley. Taste and adjust seasoning with additional salt or vinegar if needed.

Refrigerate for at least 1 hour before serving to allow flavors to meld. Bring to room temperature and toss again before serving. Add extra dressing if pasta appears dry.