Cook rice according to package instructions. Prepare other ingredients while rice cooks.
Slice cucumber into 1/4 inch slices, then quarter. Quarter cherry tomatoes.
Drain kalamata olive liquid into a small bowl; set aside.
Mix olive oil, olive juice, oregano, and salt in a small container; shake well.
Combine cooked rice, vegetables, pistachios, and olives. Shake dressing again, pour over salad, and toss gently. Serve immediately or chill for 30 minutes.
Notes
Best enjoyed fresh; refrigerate leftovers within 2 hours.