Fill a large pot with water and bring it to a boil, adding a generous pinch of salt.
Cook the orzo in the boiling water until al dente according to the package instructions.
Drain the pasta and rinse it under cold water to cool it down to room temperature.
Transfer the cooled orzo to a big mixing bowl and fold in the pesto until every grain is evenly covered.
Gently mix in the halved mozzarella pearls and cherry tomato halves.
Just before serving, drizzle with balsamic glaze if you like for an extra touch of flavor.