To flatten each pork slice, place between 2 pieces of plastic wrap or waxed paper. Working from center, gently pound pork with flat side of meat mallet or rolling pin until about 1/4 inch thick; remove wrap. Sprinkle pork with 1 teaspoon salt and pepper.
Melt butter in 12-inch skillet over medium-high heat. Add pork; cook 8 minutes or until browned, turning once. Remove pork from skillet. Add gingerroot and garlic to skillet; cook and stir 1 minute or until tender.
In medium bowl, combine cornstarch, apple juice, 1/4 cup water and vinegar; mix well. Add to mixture in skillet. Bring to a boil. Reduce heat to medium-low. Add mushrooms and pork; cook 10 minutes or until sauce is of desired consistency, stirring occasionally.
Meanwhile, in medium saucepan, combine 2 cups water and 1/2 teaspoon salt. Bring to a boil. Stir in couscous, corn, bell pepper, onions and five-spice powder; mix well. Remove from heat. Cover; let stand 5 minutes. Serve couscous with pork mixture.