Cook orzo according to package directions on a camp stove. Meanwhile, in a large bowl, whisk together oil, vinegar, oregano, basil, 1/2 teaspoon salt, and the pepper and reserve.
Drain pasta, rinse with water until cool, and drain again. Add to bowl with dressing and gently mix in spinach, tomatoes, and olives to combine. Add more salt if you like.
Make ahead Up to 2 hours, at room temperature.
PER 1-CUP SERVING 315 Cal., 44% (140 Cal.) from fat; 6.9 g protein; 16 g fat (1.7 g sat.); 39 g carbo (4.4 g fiber); 550 mg sodium; 0 mg chol. VG