Saute Chicken, Celery, Parsley And Oregano In Oil Until Browned. Add Beef, Onions, Garlic, Cumin, Salt And Pepper. Saute For 10 Minutes. Add Paprika And Cook For 1 Minute. Remove From Heat. Place Meat Mixture Into Large Baking Dish. Top With A Layer Of Mashed Potatoes. Sprinkle With Parmesan Cheese If Desired And Bake At 375 Degrees For 35 Minutes.