Irish Potato Soup
["1/2 c. margarine", "1/2 c. chopped onion", "5 medium potatoes, chopped", "1 1/2 c. water", "1 tsp. salt", "2 c. hot milk", "1/2 c. cold milk", "1 egg yolk, beaten", "pinch of cayenne pepper", "2 Tbsp. chopped parsley"]
["Saute onions in butter and add potatoes, water and salt.", "Cook until potatoes are tender.", "Either mash or put in blender with the hot milk.", "Slowly blend into mixture the cold milk and beaten yolk.", "Add pepper and parsley.", "Do not boil.", "Serve with sharp Cheddar cheese, grated."]
["margarine", "onion", "potatoes", "water", "salt", "hot milk", "cold milk", "egg yolk", "cayenne pepper", "parsley"]