Bring a large pot of salted water to a rolling boil over high heat. Add tri-color rotini pasta and cook for 9-11 minutes, or until al dente. Drain the pasta in a colander and rinse it under cool water.

In a large mixing bowl, combine the cooled, drained pasta with halved cherry tomatoes and fresh mozzarella pearls. If using, add thinly sliced red onion. Gently toss to combine.

In a small mixing bowl, whisk together olive oil, balsamic glaze, lemon juice, and minced garlic. Incorporate Italian seasoning, salt, and pepper. Whisk until emulsified.

Drizzle the vinaigrette over the pasta mixture. Gently toss to coat all ingredients evenly.

Chill in the refrigerator for 30 minutes before serving to allow flavors to meld, or serve immediately.