Cook orzo according to package instructions. Once the orzo is done cooking, drain, and run the strainer with the orzo under cold water to stop the cooking process. Set the pasta aside.
Chop the spinach, tomatoes, mozzarella, red onion, and olives. Place them in a large bowl.
Add the cooled orzo to the bowl.
Top with the pesto (see notes), lemon, and olive oil and mix everything together. Season with salt and pepper. Enjoy!