Pork Medallions with Rosemary and Mushrooms

1. Slice pork into 8 crosswise pieces. 2. Press each pork tenderloin slice to 1-inch thickness. 3. Heat margarine in large heavy skillet over medium-high heat. Brown pork quickly, about 1 minute on each side. Remove from heat. 4. Place cooked pork slices on serving plate, reserving drippings. Keep warm. 5. Add mushrooms, onion, rosemary, celery salt, pepper and garlic to reserved drippings in skillet. 6. Cook over low heat about 2 minutes, stirring frequently. 7. Add sherry; stir to blend. Return pork slices to skillet; spoon mushroom mixture over slices. Cover and simmer 3-4 minutes. 8. Place pork slices and mushrooms mixture on serving plate. Garnish with sprigs of fresh rosemary and fresh mushrooms caps, if desired.