Mix the grated American cheese, chopped hot dogs, and the cream cheese together until it is of spreading consistency.
Spread this mixture on one side of 12 of the pieces of bread. The remaining six are reserved for the top. Place six of the spread slices, spread side up, on the bottom of a suitable baking dish. Follow this by placing the remaining six slices of spread bread on top, again with the spread side up. Top with the remaining six slices of unspread bread. You will end up with a three-layer sandwich. Press down on each sandwich slightly so that the layers firmly adhere.
Mix the eggs, milk, salt and pepper together well. Pour this over the three-layer sandwiches. Cover with aluminum foil and place in the refrigerator overnight.
The following day, remove the foil cover and place in a 325-degree oven for 45 minutes (I should have left mine in longer) or until firm and just slightly browned.
For the topping, melt the butter in a saucepan; add the onion and saute until it is slightly transparent. Add the mushroom soup and cream and stir well. Continue to cook over low heat for 5 minutes or until warmed through. Add the chopped eggs and the parsley; cook for 3 minutes longer. Stir from time to time to prevent sticking.
Using a broad spatula, remove each sandwich from the baking dish to individual serving dishes. Top each baked sandwich with generous spoonfuls of the sauce. Serve piping hot.
Yield: Serves 6