Prepare sauce by combining all ingredients in measuring cup. set aside. Heat large skillet or wok on medium high. Add oil. When oil's hot, add vegetables and cook and stir until vegetables are tender but still crisp. Do not over cook. Add sauce and cook, stirring constantly until thick. Trim sides of pita bread and gently separate each into 2 layers. Brush outside of each half with oil if desired. Place 4 halves on grid oiled side down. Spoon vegetables on pita over each pocket. Top with remaining bread. Close lid and cook 3-5 minutes or until heated through and sealed.