Cheddar-Stuffed Mushrooms
["18 to 20 fresh mushrooms", "2 Tbsp. melted butter or margarine", "1/2 c. chopped onion", "1/4 c. melted butter or margarine", "1 c. soft breadcrumbs", "1 c. (4 oz.) shredded Cheddar cheese", "1/2 c. chopped walnuts", "1/4 c. chopped fresh parsley", "1/2 tsp. salt", "1/4 tsp. pepper"]
["Clean mushrooms.", "Remove and chop stems and set aside.", "Brush mushroom caps with 2 tablespoons melted butter; place in lightly buttered shallow baking pan.", "Set aside.", "Saute onion and chopped stems in 1/4 cup melted butter over medium heat until tender. Remove from heat and add breadcrumbs and remaining ingredients. Spoon cheese mixture into caps.", "Bake, uncovered, at 350\u00b0 for 20 minutes or until cheese melts and mushrooms are thoroughly heated."]
["mushrooms", "butter", "onion", "butter", "breadcrumbs", "Cheddar cheese", "walnuts", "fresh parsley", "salt", "pepper"]