Heat 1/2 cup butter and stir in flour. Combine milk and
bouillon and stir into the flour mixture. Cook, stirring,
until the sauce is smooth and thickened. Blend in the
salt, pepper, nutmeg and sherry. Stir in the cream and
remove mixture from the heat.
Cook and drain the spaghetti.
Saute the mushrooms in 2 Tb butter for about 5 minutes,
or until nicely browned. Mix Half of the sauce with the
spaghetti and mushrooms. Place in a buttered, shallow
baking dish. Make a well in the center of the spaghetti
mixture. Mix remaining sauce with the turkey and place
in the well. Sprinkle with parmesan cheese. Bake in a
preheated 400º F oven for 20 minutes.