Canadian Turbot a la Mercier

A turbot having a dark skin on both sides and the shape of chicken halibut; when dressed and clean, split it through the back, butter a small raised-edged dish, a little larger than the fish; cover the bottom with shallots, mushrooms and parsley, all finely chopped, and lay the fish on top, season and moisten to its height with a good cold court bouillon with white wine (No. 39); let the liquid boil for ten minutes over a moderate fire; cover it with a sheet of buttered paper, and finish cooking in a slack oven, basting it frequently. After removing besprinkle with chopped parsley, and serve it on the same dish surrounded with cysters a la Villeroi (No. 698).