Heat one teaspoon oil in nonstick skillet over medium heat. Add carrots and celery, stir frying about 3 minutes. Remove vegetables, set aside.
Pour remaining oil into skillet. Add pork, stir fry for about 3 minutes. Return vegetables to pan, add orange juice mixture and cashews. Cook, stirring constantly, over medium-high heat, until thickened. Serve over hot rice, if desired.