Marinate the tomatoes. In a mixing bowl, whisk together the olive oil, aged balsamic, garlic, salt, and pepper. Add the tomatoes and toss well. Set aside while the pasta cooks.

Cook the pasta. Bring a pot of salted water to a rolling boil and add the orzo. Cook according to package instructions, until al dente. Drain into a colander and rinse with cold water until the pasta is cool enough to handle.

Finish the pasta salad. Add the orzo to the tomatoes and mix in the fresh mozzarella and basil. Season to taste with salt and pepper and serve room temperature or chilled.