Cook tortellini in salted boiling water according to package directions. Drain and rinse under cold water.

Prepare vegetables by chopping tomatoes, cucumber, onion, and olives.

In a small bowl, whisk together olive oil, vinegar, garlic, Italian seasoning, salt, and pepper.

In a large bowl, combine cooled tortellini, vegetables, mozzarella, and basil.

Pour dressing over the salad and toss until evenly coated.

Refrigerate for at least 30 minutes before serving.

Toss again, adjust seasoning, and serve chilled.