When cooked, drain but do not rinse the orzo. Place drained orzo in a bowl and let cool slightly. Stir gently so the hot areas are able to cool slightly too.
Once the orzo has cooled slightly, add the pesto and stir so the orzo is coated.
1 cup pesto
Let the mixture rest for about 5 minutes then stir again and then stir in chopped spinach.
2 cups spinach
Add tomatoes and mozzarella. Stir gently until it's well combined.
8 ounces pearl mozzarella, 1 cup cherry tomatoes
If the pasta seems dry, add 1-2 tablespoons of olive oil.
Serve immediately or cover and refrigerate.
Notes
Add a dash of salt if desired.
If refrigerated, allow the salad to sit at room temperature for 5-10 minutes. Stir before serving. The pasta will often absorb the oil from the pesto over time. If the pasta is too dry, add 1-2 tablespoons of olive oil.