Drain salmon, save liquid.
Flake into large pieces. Add milk to salmon liquid to make 2 cups.
Melt butter or margarine in pan. Blend in flour, salt, pepper and nutmeg.
Add salmon liquid and milk mixture all at once. Cook on medium heat, stir constantly
until thick and smooth. Add mustard and sherry. Stir in spaghetti, mushrooms
and salmon. Turn into 1-quart casserole.
Combine crumbs and Parmesan cheese and sprinkle over top.