Cook orzo in boiling salted water 8 minutes or until tender.
Meanwhile, in large skillet, heat oil over medium-high heat. Cut pork in 1-inch chunks; add to skillet, cooking until browned on all sides, about 3 minutes. Add tomatoes; cook, stirring, until softened. Remove skillet from heat. Stir in half of the feta cheese.
Remove pot of orzo from heat. Stir in spinach; drain, reserving 1/2 cup cooking liquid.
Transfer orzo-spinach mixture to serving dish. Add pork, remaining feta and salt; toss together, adding a little of the reserved cooking liquid, if desired. Serve warm. Makes 6 servings.