Combine oil, vinegar, tarragon, lemon juice, mustard, salt and pepper in a small bowl. Whisk to blend.

In a medium bowl, toss chicken with 1/4 cup dressing.

Boil orzo in a large pot of salted water until just tender but still firm to bite. Drain. Rinse under cold water to cool and drain well.

Transfer orzo to a large bowl. Stir in remaining dressing and toss to coat. Add chicken, tomatoes, artichoke hearts, and olives. Spoon each serving into a portable insulated container, keep chilled until lunchtime.

460 cal, 19 carbs, 39g protein, 26g fat, 140mg chol, 1,000mg sodium, 1g fiber