Prepare the orzo according to package directions. Drain and set aside, rinsing briefly to prevent clumping.
In a blender (or in a jar with a tight-fitting lid) combine the olive oil, balsamic, garlic, salt, and pepper.
Transfer the orzo to a large bowl. Add the mozzarella, tomatoes, basil, and then drizzle the vinaigrette to taste (you may not need all of it, but reserve leftovers to serve with leftover orzo salad). Taste; add more salt and pepper if desired.
Leftover orzo salad can be stored in the refrigerator in an airtight container for up to 3 days. It may dry out a bit, so incorporate some of the leftover dressing.