Step 1

Bring a large pot of salted water to a boil. Cook the orzo according to the package instructions. Drain in a colander, rinse with cold water until cool, drain again, and set aside.

Step 2

While the orzo is cooking, place a small skillet over medium-low heat. Add the pine nuts and toast until golden and fragrant, stirring often to prevent burning, about 3 to 4 minutes. Transfer the toasted pine nuts to a heatproof dish to cool.

Step 3

Zest and juice the lemon directly into a large bowl. Add the pesto and olive oil and whisk well to combine. Add the cooled orzo to the bowl and stir until the orzo is well-coated with dressing.

Step 4

Add the cooled pine nuts and cherry tomatoes to the bowl. Tear the mozzarella and basil into small pieces and add them directly to the bowl. Finely dice the red onion and add it to the orzo, then stir until the ingredients are well distributed. Serve immediately or cover and refrigerate for later.