French Onion Soup
["4 large onions, sliced very thin", "2 Tbsp. butter", "4 c. brown stock", "4 circles hard, buttered toast", "1/2 c. grated Mozzarella cheese"]
["Lightly brown onions in butter.", "Add stock and cook 20 minutes.", "Place toast in heated soup bowls.", "Pour soup over and sprinkle with cheese.", "Additional cheese may be passed in a bowl. Canned consomme may be substituted for brown stock.", "Serves 4 to 6."]
["onions", "butter", "brown stock", "circles hard", "Mozzarella cheese"]