Cook the orzo according to package directions and drain.
Place the orzo in a large bowl. Add the olive oil, onion, lemon juice and zest, mint, and salt and pepper. Toss well. Serve warm or at room temperature.
Notes
This can be made up to a day ahead of time and served at room temperature. If you want to serve it warm, you can make the orzo ahead, then warm it in the microwave and add the other ingredients. If possible, add the mint right before tossing and serving, but don’t worry about it if you are just storing leftovers for another meal.