Heat oil in skillet over medium heat. Saute vegetables about 5 minutes, or until onion is tender.
Meanwhile, cut vegetarian patties into long strips. Add to skillet and gently cook on each side.
Mix together broth, vinegar, oregano, black and red pepper. Pour into skillet. Reduce heat to medium-low. Cover and simmer for 5 minutes or until vegetables are crisp-tender.
Mix cornstarch into 1/2 cup water. Stir into skillet. Continue stirring until slightly thickened.
Serve over cooked pasta, rice, or polenta and top with Parmesan cheese if desired.