Boil a bass in water to cover, adding to the water four tablespoonfuls of vinegar, six
pepper-corns, and a little salt. Melt one tablespoonful of butter, add one tablespoonful of flour and cook thoroughly. Add one cupful or more of boiling water and cook until thick, stirring constantly. Add the juice of half a lemon, half a can of mushrooms chopped fine, and pepper and salt and minced parsley to season. Bring to the boil, pour over the fish, and serve.
"I Love Cooking, and All Things Fish"