Mock Steak Diane
["1 lb. beef round steak (cut 1/2 to 3/4-inch thick)", "2 Tbsp. cooking oil", "1 small onion, sliced and separated into rings", "2 Tbsp. margarine", "1 (4 oz.) can mushroom stems and pieces, drained", "1 Tbsp. lemon juice", "1 tsp. dry mustard", "1/2 tsp. Worcestershire sauce"]
["Cut meat into 4 serving size pieces.", "Pound to 1/4-inch thickness. Cook meat, two pieces at a time, in hot oil for 2 minutes. Turn and cook 2 minutes more. Remove to warm platter. Cook onion in margarine until just tender.", "Add mushrooms, lemon juice, mustard, Worcestershire sauce, 1/2 teaspoon salt and dash of pepper.", "Heat through.", "Spoon over parsley, if desired.", "Serves 4."]
["beef round steak", "cooking oil", "onion", "margarine", "mushroom stems", "lemon juice", "dry mustard", "Worcestershire sauce"]