Stuffed Mushrooms

1/2 lb. large mushrooms
1/2 cup butter or margarine
1/2 cup minced onion
2 garlic cloves, minced
2 Tbls. chopped parsley
3/4 tsp. salt
1/4 tsp. oregano leaves
1/2 cup dried bread crumbs
1/4 cup grated Parmesan cheese

Preheat broiler. Remove stems from mushrooms; finely chop stems. Reserve mushroom caps. In 2-quart saucepan over medium heat, in hot butter or margarine, cook mushroom stems, onion and next 4 ingredients until onion is tender, about 5 minutes, stirring occasionally. Stir in bread crumbs and cheese. Spoon mixture into mushroom caps; place caps, stuffed side up, on rack in broiling pan. Broil for 8 minutes or until mushrooms are tender.